mss Methods of Filling Teeth. An Exposition of Practical Methods which will Enable THE Student and Practitioner of Dentistry Suc- cessfully to Prepare and Fill all Cavities in Human Teeth. BY RODRIGUES OTTOLENGUI, M.D.S. SECOND EDITION. with TWO HUNDRED AND SEVENTY-THREE ILLUSTRATIONS Giving Exact Representations ol all Classes of Cavities and their Management. PHILADELPHLA. : THE S. S. WHITE DENTAL MFG. CO. LONDON: CLAUDIUS ASH & SONS, LIMITED. 1899. Copyright, 1891, by R. Ottolengui. Copyright, 1898, by The S. S. White Dental Mfg. Co. Entered at Stationers' Hall, London. Preface to First Edition. THERE are already so many text-books that the question might be asked, "Why another ? " My reply gives my excuse for my intrusion. Without designing to criticise the methods of other writers, I would yet call attention to the fact that many have given us works which are largely compilations. These authors have seemed loath to leave anything unsaid which is pertinent to their subjects. In their efforts to be fully comprehensive they have quoted freely from others, giving pros and cons by men of equal authority, till the student who is a beginner is bewildered in his effort to choose. To avoid this, I decided to describe in my book only such methods as I have myself tested, believing that the student will be more benefited by adopting a single successful mode of practice than by essaying the various methods of many men. This has involved a two-fold result. First, and most important, the teaching becomes dogmatic. The charge has been freely made that "writers are not skillful dentists." This is because theory and practice are so often at vari- ance. I have endeavored to write a work which would be as practical as words could make it. There is not a case described that has not occurred in my practice. There is not a method advocated that I have not tested. The second result is that I do not give detailed directions for carrying out methods which I have not attempted. This of course makes the* book incomplete from that standpoint ; but I prefer this to being quoted as authority for that which I have not myself tested, as too many have been already. As an example of such omission, it will be observed that I do not describe methods of using non-cohesive gold foil. I can only say in defense that I have never used non-cohesive foil, and let that excuse my not treating of it. I will reiterate, how- ever, what I say in the body of the book, that I have never seen any iv PREFACE TO FIRST EDITION. need of it, nor found any man who could prove its necessity. I do not think my patients have suffered because of my lack of knowledge in this direction. Because of the fact that my work first appeared in serial in the Dental Cosmos, I am enabled here to reply to one or two criticisms which have been printed in society reports. One gentleman quotes me as advocating a broad contact-point in approximal fillings. In this, if he was correctly reported, he has misrepresented me. My advocacy of such a contact is in connection with a specified condition only, and the position which I take is one which I am ready to defend clinically or otherwise at any time. This would be an inappropriate place to discuss it. Another gentleman is reported to have said that I advise students to have as few instruments as possible, and that I myself fill teeth with a broken instrument. The first statement is accurate. I think that a man beginning the practice of dentistry should not purchase many instruments until he has had the experience which will lead him toward a wise choice of such an assortment as will best suit his individual peculiarities and requirements. The second statement is inaccurate, I simply say that a good filling may be inserted with a broken instru- ment. The point here was in reference to whether the point of a plugger should be serrated or smooth. A broken point is neither the one nor the other, yet may be a good point. While it is not my practice to fill teeth with a broken instrument, as suggested, I could easily demonstrate that as good a filling can be inserted in that way as with the best new plugger. Again I say it is the man, not the tool. Let me say here, as I have said in the body of this work, I do not make any broad claims for originality in connection with the methods described. If there is any originality at all, it is in the method of teaching, rather than in the thing taught. To offer the profession, and especially those just entering it, a work advocating methods entirely my own would be to ask the adoption of modes of practice not in common use, and therefore not sufficiently well tested. I have no sympathy with those who are constantly crying out, "That is my method; I invented it.'' The chief interest to the student must always be in a thorough knowledge of the method itself. rather than in the name of its originator. PREFACE TO FIRST EDITION. V To those, therefore, who will find a description of their original methods in my book I have only to say, " Gentlemen, I thank you for what you have taught to me, and am now in turn trying to teach it to others." I wish also to extend my heartiest gratitude to the hundred or more dentists of this country and Europe who, though strangers to me, have written me kindly letters of approval during the progress of this work. Many times have such letters proved a solace to me when hand and brain were tired, and so have been an incentive to continue. I thank them. RoDRiGUEs Ottolengui, M.D.S. 115 Madison Avenue, New York, September i, 1892. Preface to Second Edition. IT is just six years since the preface to the first edition of this work was written, and now a revised or second edition is ready for publication. During this lapse of time what advances have been made in our profession? To know certainly what, if any, theories have been advanced which would necessitate a change in the text, it has been necessary to review all that has been printed touching the subject, either in text-books or in our magazines. This has been done at a cost of months of labor, during which ' * spare time' ' has been devoted to this reading. In a few instances the teaching of other men or of office experience has caused me to alter passages or to add to the text. When no changes have been made the text has been left in its original form, not to avoid the work of rewriting, but because nothing in the literature or in my own experience has seemed to render a new teaching necessary. Thus the book may be considered throughout as representing the views which I hold to-day. It will probably be noted, with surprise, that no mention of cata- phoresis is made in this edition. This is not because I do not ap- preciate the importance of this aid to the dentist, but rather because I hesitate to advocate methods which have not yet been finally adopted. Cataphoresis is yet in its infancy, as appHed to dentistry, and methods now in vogue may become obsolete within a year. ^Perhaps should a third edition of this work ever be offered, it may be possible then to describe definite methods sanctioned by universal adoption. R. Ottolengui, M.D.S. 115 Madison Ave., New York, September i, 1898. CONTENTS. CHAPTER I. PAGE General Principles involved in the Preparation of Cavities — Removal of Decay — Retentive Shaping — Intentional Exten- sion — Directions for Forming Cavity-Borders — Shaping Enamel Margins i CHAPTER 11. General Principles involved in the Filling of Teeth — Methods of Keeping Cavities Dry — The Rubber-Dam — Ligatures — Clamps — Leakage — The Napkin — Chloro-percha — Wedges vs. Separa- tors — The Uses and Dangers of Matrices 28 CHAPTER II L The Uses of Various Filling-Materials— Methods of Manipula- tion — Materials of Minor Value— Gutta-percha — Oxychlo- ride of Zinc — Oxyphosphate of Zinc — Amalgams — Copper Amal- gam — Gold 49 CHAPTER IV. The Relative Values of Contour, and Flat or Flush Fillings — The V-Shaped Space in its Relation to the Gingiva — The Restoration of Superior Lateral Incisors — Slight Contours — Regulation of Teeth by Contour Fillings — Departure from Original Form — True Contouring— Treatment of Masticating Surfaces — Contouring with Gold — With Amalgam — With the Plastics in connection with Gold Plate — Use of Screws — Cases from Practice requiring Odd Methods 89 vii via CONTENTS. CHAPTER V. PAGE Special Principles involved in the Preparation of Cavities, and in the insertion of killings — consideration of approxi- MAL Cavities IN Incisors — In Cuspids — In Bicuspids — In Molars. 114 CHAPTER VI. Special Principles involved in the Preparation of Cavities AND THE Insertion of Fillings — Cavities in the Masticating Surfaces — Incisors — Treatment of Imperfections — Of Frac- tures — Of Abrasions — Of Malformations — Cuspids — Bicuspids — Molars — Oxyphosphates in Combination with Gold — Uniting Teeth by Bar and Filling 136 CHAPTER VII. Special Principles involved in the Preparation of Cavities and THE Insertion of Fillings — Sensitiveness at the Tooth-Neck — Erosion — Green-Stain — True Caries — Festoon Cavities — The Labial Surface — The Palatal — The Lingual — Buccal Cavities — Temporary Fillings — The Finishing of Fillings 163 CHAPTER VIII. Methods of Filling the Canals of Pulpless Teeth — A Study of Tooth-Roots— Methods of Gaining Access to and Preparing Canals — Methods of Cleansing Root-Canals — When and How TO Fill Root-Canals 190 Index 217 METHODS OF FILLING TEETH. CHAPTER I. General Principles involved in the Preparation of Cavities- Removal OF Decay — Retentive Shaping — Intentional Extension- Directions FOR Forming Cavity-Borders — Shaping Enamel Mar- gins. Now that the dentist is no longer to be denominated the ' ' knight of the forceps, " it is fundamentally essential that he who would become a conscientious practitioner should be able to determine whether a tooth be salvable by the insertion of a filling ; to decide which of the many materials now in use will best attain the end in view ; to prop- erly prepare the cavity for the reception and continued retention of the filling, and be capable of scientifically and skillfully placing it so that it will be as nearly perfect as the attending conditions will permit. This much has been accomplished by a goodly number of the dentists of the past and present. Something more will be expected of the dentist of the future. He will be asked to abandon the assertion, "Madam, your tooth has decayed around my filling, but the filling was all rights Undoubtedly there are teeth in which it may be impossible to prevent recurrence of decay, but it is equally true that in too many cases when the ' ' tooth decays around the filling' ' the filling was not "all right." It is opportune, therefore, to discuss these questions more in detail than has been done heretofore. Those whose fillings are frequently returned to them in a leaky condition are compelled to adopt one of two propositions : Either their work is inefficient, or else the teeth upon which they have operated are of poor quality. It is but human to lean toward the latter explanation. The position, however, is rarely tenable. The argu- ment used is this : " If the tooth decayed when it was perfect, why should it not do so after it has been filled ? I cannot be expected to build 2 METHODS OF FILLING TEETH. better than did the Creator. ' ' This sentiment was loudly applauded at a national meeting, leaving the impression upon the mind of him who analyzed the situation that there were many present anxious to adopt this specious excuse for the failures which had attended their efforts. The fallacy lies in this : While it is perhaps true that no material exerts any therapeutic influence beyond the mere mechanical stopping of a hole and restoration of contour, it is also true that, given a tooth, and certain conditions under which it is attacked by caries, the caries will occur invariably at a specified situation. There- fore, when the cavity is filled scientifically the tooth is safer than ever, because the vulnerable point is now occupied by a material which will resist destruction by caries. If decay occurs along margins, it is because' those margins were improperly made either as to shape or position, or else because the filling was unskillfully inserted or finished. An ideally completed filling is one which is given as high a polish as the material used will permit. Those who argue for ' ' dull finish," because less conspicuous, forget that "high polish" means smoothness, which quality is a prerequisite. The student watching his preceptor is almost invariably impressed with the idea that only a few principles are involved, and that the operation of filling a tooth is purely mechanical. As soon as he acquires the knack of packing gold and producing a polished surface afterward, he considers that ' ' he knows it all. " It is only after several years of bitter experience at refilling teeth for his own patients, that he begins to suspect that perhaps there is more in this branch of dentistry than his mind had grasped. Let us now con- sider the subject in detail, from the point of view that there is more involved in it than mere mechanics. General Principles involved in the Preparation of Cavities. Removal of Decay. — When a cavity has been properly prepared, the tooth is half filled. The most beautifully polished, soUd, well- formed filling will fail if the cavity has not been skillfully shaped. To the mind of the layman it would seem idle to discuss the pro- priety of leaving any decay in a cavity. It is not uncommon to have a mother say, ' ' Doctor, please be sure to take all the decay out, as I don' t want Willie' s tooth to trouble him again. ' ' To her mind, safety lies in thorough cleansing. It seems a rational proposition, yet it has been argued by high authorities that there are frequently occurring cases where it is best not to remove all the decayed dentine. This is a grave error. With rare exceptions it is imperative that every trace of caries should be obliterated. The tooth about to receive a filling should be as wholly healthy as it can be made. REMOVAL OF DECAY. 3 It has been claimed that decay covering a pulp may be left in place and sterilized with safety and advantage. This sterilizing is usually done at the sitting at which the filling is placed. I have followed this advice in a few cases, where, in the front of the mouth, it seemed best to take every precaution to avoid destruction of the pulps and consequent discoloration. In every case I have afterward removed the fillings, because of a bluish appearance which subsequently presented, showing that despite the fact that the edges were yet perfect, decay was pro- gressing internally. This shows that a perfect gold filling will not stop decay if carious dentine is left in the cavity. Experiments made by Professor Miller are in harmony with this experience, since he shows that the germicides upon which most reliance has been placed are in- effectual unless left in a cavity much longer and in greater quantity than has been our practice. When our chemists shall have dis- covered for us a sterilizing agent the use of which will assure us of a discontinuance of carious action, in already carious dentine, then, and not till then, will there be any argument worth listening to against the assertion that it is ?naipractice to Jill over decay. Indeed, in the light of present knowledge, the dentist must not only eradicate the truly carious dentine, but he should also deal with the zone of " infected " dentine which lies adjacent. TofuUy comprehend this term, " ' infected' dentine," which I intro- duce for the consideration of scientific and prophylactic practitioners of the future, we must understand the causes which produce dental caries, as well as the modus operandi of the agencies at work. With- out entering into a technical discussion of the various theories which have been advanced, I may say that I at present accept that expla- nation of dental caries which has been demonstrated so admirably by Dr. J. Leon Williams, a brief summary of which is as follows : Human enamel is composed of a series of globular bodies, super- imposed the one upon the other, these bodies and the rods them- selves being held together by a cement-substance. In the production of dental caries, first, there appears imposed upon and firmly attached to the non-carious surface of enamel a felt-like stratum of micro-organisms. Second, these micro-organisms excrete a virulent acid, which has the power to dissolve the cement-substance, which normally binds the enamel-rods and their formative sections, the globular bodies. Third, this acid dissolution primarily follows the spaces between the rods ; thus, to use an analogy, boring shafts or well holes, and thereby offering entrance to the multiplying bacterial cells, which, following the course marked out with their own excre- tions, grow from the surface internally, penetrating the enamel as rapidly as the dissolution of the cement-substance will permit. Subsequently, and to some extent coincidentally, the excreted 4 METHODS OF FILLING TEETH. acid attacks the cement-substance of the rods themselves, separat- ing them into their original formative sections. The penetration of this acid solvent is greatly in advance of the inroads of actual decay, and the dentine itself may be affected, and perhaps infected, while there might be but slight evidence of decay at the external surface of the enamel. It may be well to explain clearly my differentiation between " affected " and " infected." I conceive the tooth-substance to be " affected" when the acid excretion of micro-organisms has dissolved the cement-substance, however slightly : when the dissolution has progressed further, so that shafts have been bored, into which bacterial cells have penetrated, the tissue is " infected." When the enamel-rods have been separated into their original globular bodies, we have carious tissue. The lines of positive demarcation between these three stages cannot be certainly indicated, as the whole is a progressive disorganization. We may well remember, however, that all tooth bone, adjacent to caries, is affected tissue, and it would be wise to give germicidal treatment prior to filling. Where we meet dentine which is changed in character, though not perhaps absolutely carious, such as that which has been termed softened dentine, we may henceforth consider it to be " infected," and if in a special case we deem it unwise -to remove this infected tissue^ we should remember that it contains the agencies which produce decay, and at least we should treat it with a reliable germicide. Infected dentine requiring special treatment is always present in those teeth from which we remove carious dentine in leathery layers. To excavate such a cavity, use spoon excavators only. Never employ a hatchet, or a hoe, or an engine-bur, unless needed for shaping after the decay has been removed. With a spoon begin at a point farthest away from the pulp, and gently lift the outer edge of a layer. Having thus disengaged it, proceed to lift it around its whole circumference, and then work gradually toward the center till it can be taken out of the cavity. Repeat this as often as a layer can be started at its circumference. As soon as the last distinct layer has been removed, scrape all the walls vigorously, removing even the soft- ened dentine which may be clinging to them. The cavity will now be clean, but the bottom of it will be soft. Still using the spoon, scrape the bottom very gently, starting at the circumference and approach- ing the center, removing all small particles which may be thus disen- gaged, without actually cutting. A reliable germicide should now be used on cotton, the cavity sealed with a phosphate cement, and so left . for two or three days, when the filling may be inserted with safety. Infected dentine may be found beneath other than leathery decay. When it is found underlying decalcified enamel, the enamel will come RETENTIVE SHAPING. 5 away as a white, chalky powder, and the dentine beneath need only be removed as required for the retention of the filling. This condition is rarely observed except under "green-stain," and the destruc- tion is a decalcification, rather than true caries. A corundum stone should be used to remove the stain, when the decalcified enamel will readily be distinguished by its chalk color. The dentine beneath is infected, but as the destruction is superficial there is little risk of exposing the pulp, for which reason no special caution is needed beyond the usual care when operating on healthy dentine, not to cut deeper than is actually necessary to correctly shape the cavity. It may be said in passing that this decalcification of enamel due to or accompanying "green-stain " is usually associated with highly sensi- tive dentine. This is fair presumptive evidence that the dentine is undergoing a change. There is a class of teeth which appear stained, in which a seeming decalcification of enamel will be found, which teeth, however, re- quire the most conservative attention and skillful treatment. These teeth show brownish or otherwise discolored spots, usually extending from one of the lateral surfaces up to, and sometimes into the occlusal. These are not stains which are removable, but are de- fectively calcified tooth substance. Occasionally such a spot will be found in a perfectly shaped tooth, the usual enamel lustre being present ; again the surface will be irregular but still somewhat polished. If these spots are entered with a bur, the enamel and sub- jacent dentine will be found chalky, and often very extensive cutting will be needed to reach firm tissue. If a filling is required all this improperly calcified tissue must be removed until strong margins are obtained. Unless absolutely necessary, however, it is usually best to leave such places undisturbed, because not infrequently they appear to be immune to caries for years, even though neighboring teeth may be badly affected. Retentive shaping. — The cavity cleansed of decay, the next impor- tant object is to so shape it that the filling cannot be dislodged mechan- ically after it has been inserted. To accomplish this sometimes taxes the utmost ingenuity of the most experienced, so that binding rules cannot be formulated to cover all conditions. It will therefore be best, in order to describe methods covering a wide field, to take up individually the more common cavities, but before proceeding to that discussion I shall present here a few general principles. The great desideratum is to so form the cavity that the visible ex- ternal surface of the filling, when placed, shall have a smaller diameter than some portion which is within the cavity. We should thus have a mass occupying a cavity whose orifice would not permit the passage of its greatest diameter. Such a filling could not be removed mechan- 6 METHODS OF FILLING TEETH. ically, except in pieces. If the material therefore were durable, the fill- ing would be permanent as long as the opening was not enlarged by decay or fracture. There are, however, other considerations which may make it imprudent, or impossible, to follow this rule, as, for exam- ple, when such a course would cause the excavation to approach the pulp too nearly. Dentistry is in many respects governed by mechan- ical laws, but when we come to apply mechanics to living tissues there are frequently points at which the ordinary laws must be set aside and reason allowed to hold sway. In the case of the retention of a filling, reason would set aside one law, however, only to adopt another, which, though not so general in its significance, would be indicated in a special instance. Where it becomes unwise to attempt to enlarge a cavity till its orifice is its smallest diameter, there are usually at least two direc- tions in which extension may be made, which will sufficiently serve to hold a solid filling. Much may be gained at times by judicious rough- ening of the surface of the cavity. Fig. i exemplifies such a case. Fig. I. Fig. 2. Fig. 3. Fig. 4. The crown of a molar has become denuded of enamel, and the dentine is highly sensitive. A few dovetails made with a sharp rose bur will serve to retain a filling, though the orifice has the largest diameter. Again, there may arise cases where the destruction leaves, not a cavity proper with an orifice, but merely a loss of substance with no retentive shape whatever. It is in these cases that the ingenuity of the dentist is taxed. In many instances well-placed screws are of great advantage. These will be described later. In the simpler forms of cavities, those which may be described as having surrounding walls and orifices, the rule first mentioned must usually be applied, but judgment must be employed. These cavities are of three classes, approximal, crown, and surface, the latter in- cluding palatal, labial, lingual, and festoon cavities. I shall consider approximal cavities first, because they are the most difficult, and demand more skill and judgment. Fig. 2 is a cross-section through an incisor which has been filled. A casual glance demonstates the fact that the filling could not be dislodged, because the greatest diameter, which is in the line a, rapidly, so that thorough condensation may be had, as well as per- fection of border. It is a pleasure, when such a filling is placed, to be able to polish it like a mirror, and have the borders so well made that 1 78 METHODS OF FILLING TEETH. even under a strong magnifying glass they appear as fine as a hair. This will rarely, if ever,, be possible where the beveled edge is depended upon. Fig. 189 shows a curious cavity which occurred once in my prac- tice, and I introduce it because the method of management will be instructive. This cavity originated in one of those pits which are not uncommon upon cuspids, and which result from malformations. It presented as a small but distinct cavity. On preparing it, to my surprise I noted that, however deep I went, the bottom of the little pit still showed as a black spot. Using a mouth-mirror, I examined the palatal side, and there found a corresponding pit, at a point exactly opposite to that on the labial face. Further exploration dis- closed the fact that caries starting in each had met, so that when removed there was a hole completely through, from the labial to the palatal surface. Here was a cavity without any bottom to it. The dam being in place, I stopped up the palatal orifice with oxyphos- phate, which I allowed to set hard. I then filled the cavity in the labial face, after which I removed the oxyphosphate and completed the filling from that side, succeeding in obtaining cohesion for my first pellet with the gold packed from the other side, so that when finished there was a solid gold filling from side to side. This idea, conceived in connection with this particular cavity, has been useful in many directions. I have elsewhere alluded to it. The common cavity at the palatal aspect of the anterior teeth is simple enough, except that great caution is necessary to prevent injury to the pulp. This cavity may be met in either central, lateral, or cuspid, but will most often be found in laterals, occurring in the sulcus. Its preparation is best shown by a sectional view such as Fig. 190, where we see how near any cavity at this point must approach the pulp. I prefer a small rose bur to open the cavity, but any soft decay which may be present must be removed with small spoon exca- vators. As soon as the limits of the cavity are reached,' it will probably be found to be of retentive shape ; but if not, extension must be carefully attempted, and must be directed parallel to, or away from, the walls of the pulp-chamber, as seen in the figure. I have seen a palatal cavity neglected till it presented as shown in Fig. 191. If we look at this from a sectional view, as in Fig. 192, we see at once that the pulp is in danger. Nevertheless, this cavity is quite similar to that shown in Figs. 186 and 187 as occurring on the labial surface. As in that case, grooves may be made laterally at a, «, escaping the pulp. But, unlike the labial cavity, these grooves can be connected in the palatal cavity, because of the fact that on this side there is a bulge which permits this procedure in safety. The retaining groove, therefore, becomes a horse-shoe, as indicated by the dotted lines a, a. LINGUAL CAVITIES. 1/9 As in the labial cavity, a slight shoulder must be formed toward the incisive portion, in order to avoid a bevel, and so assure a good border to the gold. The same cavity in a cuspid is much simpler. After forming the groove, deep extensions may be made at the gingival angles, owing to the fact that there is a sufficient amount of tooth- substance to make it safe to form strong anchorages. There is another difference between the labial and the palatal cavity, which must be noted. Of two cavities having the same depth, the palatal will reach nearer to the pulp than the labial. This is because the labial surface is convex, whilst the palatal is concave. Consequently in palatal cavities it is often wiser to adopt the oxyphosphate method of starting the gold filling. Where this is done, the gold is pressed into the mass of oxyphosphate toward the incisive edge. When set, the oxyphos- phate is removed from the retaining grooves and the gold extended into them, thus securing the filling without special dependence upon the adhesive property of the plastic, which is inserted as an insulator. Fig. 190. Fig. 191. m A lingual cavity in the bicuspids or molars is a rarity, and, when found, usually extends along the gum-border. In nine cases out of ten an ill-fitting clamp has caused the mischief The lingual surfaces of almost any of the lower teeth may almost be said to be exempt, save where the clamp induces decay. This is perhaps because the tongue and fluids of the mouth keep the parts washed and cleansed. Never- theless, I have seen long, narrow cavities, partly under the gum, all along the Hngual surfaces of lower molars. Their preparation may require that they be packed with cotton for a day, in order that the gum may be forced away. This accomplished, a rose bur which will cleanse the cavity of decay will usually leave it retentive in shape. If not, a slight extension at each end is all that is needed. Here is a place where I might almost say gold should never be-employed. To insert a perfect gold filling in such a position, with all the obstacles offered by situation, saliva, and presence of the tongue, would require extraordinary ability, and even then would be accomplished at an 1 80 ME THODS OF FIL L ING TEE TH. expense of time and pain that scarcely excuses the effort. An amal- gam fining, on the contrary, may be placed with rapidity and ease, and if properly polished afterward will serve all purposes. In the superior jaw similar cavities are more common, and at the same time less difficult. I will introduce here a case from practice which offered unusual features. Fig. 193 shows a first molar in which is seen a narrow cavity, <2, along the palatal side P near the gum, whilst a second cavity, b, appears at the palato-approximal angle. At first glance one would naturally say that they should be connected and filled as one cavity. This I could not do, for the reason that there was great diffi- culty in placing the dam. The twelfth-year molar had not sufficiently erupted to retain the clamp, which therefore was necessarily placed over the affected tooth. Again, this tooth was so conical, and both of the cavities were so near the gum, that I found it impossible to place the dam and tie a ligature before placing the clamp. Neither did I succeed in tying a silk around the tooth after placing the clamp. As a consequent result, I found that though I could force the dam back with the clamp so that I could fill either cavity, moisture would leak in through the other. In this dilemma I filled the "cavity b with gutta-percha temporarily, then placed the dam and filled the cavity a with gold, subsequently filling the other. I filled these cavities with gold,' for the reason that the teeth were excessively sensitive, and the young man was obliged to wear an obturator, which needed clasps to hold it in place. I felt satisfied that, if filled with amalgam, the gold clasps in contact with amalgam in this special instance would prove mischievous. As I decided to fill the two cavities separately, I could not form any extension in either at the end near the slight separation of dentine at c, without under- mining that point. I therefore made an extension at the opposite ends in each, and formed slight undercuts along the length of the cavities. In each case the first pellet was packed into the pit at the end,' and the gold built forward toward c. The patient was tipped back so that I could get direct view of the work looking across the mouth, the tooth being upon the left side. These two fillings were placed three years ago, and though a fixture with clasps has been worn constantly since, no annoyance has been reported. Buccal cavities are difficult or simple in proportion as they are large or small, sensitive or otherwise, and near to or distant from the gum. The simplest form is the small, almost circular cavity found in the buccal sulcus, oftener in the lower than in the upper teeth. Their preparation is easy, necessitating the use of a rose bur which will not BUCCAL CAVITIES. l8l quite enter the orifice, thus shaping the borders at once as it is pressed through into the dentine. The removal of all carious material, and a slight internal enlargement, will suffice where amalgam is to be used. For gold, I should make slight extensions obliquely in opposite direc- tions ; this not so much as a retentive precaution as to facilitate filling, since the cavity so formed will be more readily managed than one which is perfectly regular and round. There is a strong temptation here to wedge in a few large pellets, burnish, and call the tootli filled. The true method is to use small pieces here as elsewhere. I should choose gold for all such cases, except where the youth of the patient might make it advisable not to impose a lengthy operation ; then use amalgam, explaining that gold will be inserted later in life. Where the sulcus is well marked it should be cut out, the cavity being extended toward, but not necessarily into, the-crown. This will produce an oblong filling. The retentive formation in such cases would be an extension toward, the gingival end of the cavity and lateral, but slight undercutting, effected with a wheel bur. There should be no undercut toward the crown, lest by weakening that Fig. 194. Fig. 195. point fracture result under the forces of mastication. Larger cavities may be met, of all conceivable shapes. There may be two, or even more, distinct cavities in the buccal surface of a single tooth, and in each instance the operator will be called upon to connect them or fill •each separately, as his judgment shall dictate. The main fact will be to determine whether the fillings will be better retained separately, ■or in one cavity. Fig. 194 presents a good study. Three cavities are seen in the buccal surface of a molar. The smaller one, «, is in the sulcus, and quite near it is another, b, extending along the gum- border. At ^ is a third, which almost encroaches upon the approxi- mal surface, being near the angle. Here it is plain that if in cavity a my instruction to make a retaining extension at the gingival end were obeyed, the drill would emerge within the cavity b. True, the smaller cavity could be filled, depending alone upon lateral undercutting ; but when cavity b is similarly prepared it would be found- that the separa- tion between the two would be extremely frail. Here, then, it would be best to unite and fill the two as a single cavity. Cavity c, however, is distant, and in sufficiently sound territory to permit of filling it .separately. Fig. 195 shows the tooth prepared for filling. The dotted 1 82 METHODS OF FILLING TEETH. lines a, a, indicate the retaining extensions depended upon for the larger cavity, whilst in the smaller there is merely a general undercut, slight toward the crown, and deep enough toward the gingiva to allow the first pellet to be wedged securely, if gold is to be used. The choice of gold or amalgam might depend, as before, upon the age of the patient, or it might be decided in accordance with the difficulty met with in placing the dam, and the amount of moisture. The general arrangement of the larger cavity in Fig. 195 is the one to be depended upon in all ordinary buccal cavities. This is, exten- sions at the anterior and at the posterior gingival angles, with grooves following the other borders, decreasing in depth as the crown is ap- proached. This applies more particularly to cavities resulting from true caries. Those found under green-stain will be much more per- plexing. To illustrate, I will give two examples. The first is seen in Fig. 196, where, the stain having been removed, we find three small cavities along the gum-border, whilst the enamel p. , between and around them is more or less decal- cified, as indicated by the stippHng. The prepara- tion of this necessitates the free use of a bur, form- ing a single cavity which will include the entire affected area. This may result in an oblong cavity along the gum-border having nearly parallel bor- ders. More commonly, however, the enamel will be found softened toward the crown along the sulcus, so that, when prepared, the cavity will be approximately shaped like the larger one in Fig. 195. A most dis- heartening condition is where, whilst extending the cavity in the direction of the decalcified territory, it is found that one or both approximal surfaces have become affected. The rule, however, is not to be relaxed, even though the procedure as directed will lead the dentist entirely around the tooth, thus forming a cavity com- pletely encircling it. This occurred to me once, and I found much difficulty in placing amalgam, until I hit upon a method which led me out of the dilemma. The difficulty was that after packing the amalgam into the posterior approximal part of the cavity, thence into the buccal, and so around into the anterior approximal, as soon as I 'endeavored to fill the palatal part I found myself dislodging that already packed. Add to this the inroads of moisture, because of the fact that I was obliged to depend upon the napkin, and it is seen that the amalgam, becoming wet, could not properly be forced back into place. I tried beginning at different points, but invariably when I came to completing the circle, dislodgment resulted. Finally I succeeded thus : I fashioned a band of German silver, somewhat wider than the cavity. I began by filling the palatal part of the BUCCAL CAVITIES. 183 cavity, packing the material part way into the approximal portions. Next I placed my band in position around the tooth, covering the amalgam already in position, and allowing the two ends to extend forward between the adjacent teeth. Around this band I placed Fig. 197. waxed flax thread, the ends lying loose. The condition at this point is shown in Fig. 197, which gives the buccal side of the tooth still unfilled, the relation of the band and flax being seen. The filling was continued from the posterior approximal part around into the buccal, when the band was bent down over it. Then the anterior part was similarly treated. When both ends of the band were thus turned down, the flax was tied, securely holding the band in place, whilst as it was drawn tight it compressed all the amalgam into the cavity uniformly and simultaneously, even forcing out a slight sur- plus of mercury. This was left in position until the next visit. Since then I have frequently resorted to this method of tying a band around an amalgam filling where similar conditions existed, even though they have been less extensive. It is a good precautionary measure where amalgam is placed in a large but shallow buccal cavity, as well as in many other conditions of anomalous shape, where, after filling, there might be danger of fracture before the mass has hardened. The second type of cavities found in connection with green-stain is where the entire surface seems more or less decalcified. Fig. 198 gives an extreme case. Where the depredation is less, so that the crown is not so nearly approached, the borders are simply to be formed into regular curves, and the retaining arrangement will be the same as in Fig. 195, a, a. Where the decalcification has been as great as shown in Fig. 1 98, it will generally be wiser, if not actually necessary, to extend the cavity into the crown, and then form a groove under all borders. In many instances this will be made simpler by the presence of a filling in the crown, which can then be removed. Only in the smallest buccal cavity, found under green-stain, would I attempt a gold filling. With the larger, and especially where the gingival border passes beneath the gum-margin, I prefer and advise amalgam. An alloy which has a percentage of copper in it has done Fig. ic 1 84 METHODS OF FILLING TFETH. better service in my practice than any other. No filhng, however, will endure, if green-stain supervenes, as the enamel around it will be readily attacked and destroyed, as in the first instance. There is one other kind of cavity which I promised to describe, though not strictly a surface cavity. In fact, it may scarcely be called a cavity at all, being, if anything, two cavities. In the mouths of old people, recession of the gum not infrequently progresses to an extent which would seem to menace the tooth. So much of the root is exposed to view that it is marvelous that the tooth should not be loose. Yet often we find such teeth quite firm, although in the molar region the recession has been so ex- tensive that the bifurcation is plainly in view. As a result of this, a lodging-place for food being afforded, occasionally caries attacks the inner sides of the roots, until the pulps being approached some pain is felt, and the patient comes in for relief. „ Any endeavor to prepare separate cavities in each root would be unwise, for even if successfully filled the space between the bifurcation would continue to act as a repository for debris, so that caries would recur. I treat this space as though it were a cavity, simply removing as much caries as possible, when a naturally retentive shape will result. Where the gum is irritated so that it bleeds easily, I like gutta-percha, and prefer the pink to the white. Where the gum is firm, and the pulps not exposed, or else dead, I fill with amalgam. My method is to cut a piece of clean tin foil of such a shape that it can be placed between the roots, covering the gum, thus forming a floor against which to pack the amalgam. When the filling is in, the projecting end of tin is turned up and burnished into the amalgam. In Fig. 199 we see the space between the buccal roots of a molar, and at a the tin foil. Temporary Fillings. • Passing from permanent, I may profitably discuss temporary fill- ings. By temporary fiUing I do not mean a probational filling. The latter term should imply a filling placed in a tooth where some doubt exists as to the advisability of inserting a permanent filling of metal. It is therefore usually of oxyphosphate or gutta-percha. Whilst in a measure intended to serve a temporary purpose, the fact that the tooth is in a doubtful condition of health renders it impera- tive that the filling should be placed securely and thoroughly, so that it may remain undisturbed as long as possible, thus affording the tooth ample time for full restoration to such a state of health that it TEMPO RAR \ ' FILLINGS. 1 8 5 will no longer be doubtful whether the final filling of metal may be inserted. Temporary fillings, then, are those which cover dressings placed within a cavity for medication ; or those inserted to tide over a few days until more convenient to fill ; to force the gum away from cavity- borders, or for similar strictly temporary purposes. The man who indifferently packs in a temporary filling, with the idea that " it is only for a day," leaving surfaces rough and edges overlapped, is a sloven. Moreover, he is careless of the comfort and interests of his patient. Nowhere is the axiom truer that if a thing is worth doing it is worth doing well. The most important temporary fillings are those which cover arsen- ical dressings. Arsenic which is not thoroughly sealed within a cav- ity may cause serious damage, the more so as it must be allowed to run its course, which may involve the entire bony socket of the tooth, so that the tooth itself is finally lost.* The first caution, therefore, is to observe that where a cavity presents partly filled by hypertrophied gum-tissue, arsenic should not be applied at the first sitting, unless special reason should make it essential, and no need of such haste would excuse the procedure unless the hemorrhage consequent upon the removal of the hypertrophied tissue could be absolutely con- trolled. Ordinarily a sharp lancet should be used for removing this •excessive growth, and a saturated solution of nitrate of silver very carefully applied to the remainder. A dressing carrying some medica- ment which will act soothingly upon the aching pulp should then be applied, and this covered with a temporary filling. I may as well say at once that sandarac varnish on cotton is a filthy combination to place in the mouth. In a few cases it will serve better than anything else, but in the great majority of instances it can and should be dispensed Avith. Its main advantage is when it is desirable to force resistant gum-tissue away from a cavity- border, when usually it will serve the purpose perhaps better than more cleanly fillings. In the case above described I should use the temporary stopping furnished at the depots, which is a combination of gutta-percha and wax. This is to be had of two colors, pink and white. For teeth which will peremptorily need attention at the next sitting, use the pink, whilst when a point is reached where the tooth may be allowed a few days' rest, use the white. In this way the dentist can tell at a ■^ Where serious results obtain from poisoning the gum with arsenic, the treatment is to dress the part locally with tincture of iron ( Tinctura Ferri Chloridi), and to administer internally the hydrated oxide of iron {Ferri Oji:- iduni Hydratuni), or better still, the same preparation with magnesia {Ferri Oxiditm Hydratmn cmn lilagtiesia) . 1 86 METHODS OF FILLING TEETH. glance from the color of the temporary stopping whether the tooth requires immediate attention, or whether it may be passed whilst others are filled. In the case being discussed, then, the pink stopping would be used. At the next sitting this would be removed, as well as the cotton under it, and it would be found that the gum would be in such a condition that arsenic could be inserted. I will pause here to state that I am not discussing the advisability of using arsenic, but am simply telling how to use it where the dentist does depend upon it. The arsenic being placed carefully upon the point of exposure of the pulp, the temporary stopping must be made so soft that it can be placed without undue pressure. If it seems doubtful that this can be accomplished, it will sometimes be better to use wax, which can be made m^uch more plastic. There is one point to be emphasized. Where the exposure is in connection with an approximal cavity, care must be observed that the temporary stopping is not crowded below the gum, as this will often cause more pain than that experienced from the arsenic. With warm burnishers this filling should be trimmed to proper shape, and made thoroughly smooth. It should approximately restore contour, and should not be so full that it would interfere with occlusion. Often when the cavity is of poor shape, the burnisher may be made so warm that it slightly melts the stopping, when if passed along the borders all around, it will compel the adherence of the material. There will occur cases where the cavity is of such a nature that though the dentist desires to use arsenic, he will recognize at once that, if covered with temporary stopping, the dressing will most pro- bably be displaced. The procedure in these cases is to have the parts as dry as possible, with dam or napkin as is most feasible, and after applying the arsenic, cover with a thin oxyphosphate, which, adhering to the cavity, leaves an assurance of safety. The cavity can be shaped properly for retaining the permanent filling, of course, the trouble in the first instance being that excavation whilst the pulp is aching would be painful. After the removal of a pulp, or where the pulp has been dead for any length of time, so that the cavity is necessarily deep, especially in molars, the temporary filling need not be exclusively of temporary stopping. In large approximal cavities, considerable cotton may be placed over that which carries the medicine, and only the cuter part covered with the temporary stopping. This renders subsequent removal less troublesome. Again, where a large opening in the crown ie present, in addition to a fair proportion of temporary stop- ping, it will be well to use gutta-percha for the exposed surface, as that material will better withstand the force of mastication. THE FINISHING OF FILLINGS. \%7 Where it is desired to fill a large cavity loosely, and yet seal it up sufficiently to keep it clean and protected from the ingress of food, cotton dipped in chloro-percha will be found much better than cotton and sandarac. When cotton and sandarac is to be used, as for pressing away resistant gum-tissue, the cotton should be barely touched to the varnish. Then open the pellet, and fold it again so that the sandarac is inside. This will make a more cleanly plug, whilst giving the outer cotton a chance to swell by absorbing moisture. The Finishing of Fillings. The final success or failure of a fiUing largely depends upon the finishing or polishing. A number of points in connection with the various materials are of special interest. Gold. — A gold filling, when dismissed, should appear like solid metal, smooth at every point and highly polished. Unless there is good reason for postponement, the finishing should immediately follow the insertion of the filling, before removal of the dam. Exception to the rule, so far as the removal of the dam is concerned, would be where its presence would interfere with the polishing, or where nothing is gained by leaving it in place. The judgment of the operator would decide. Approximal fillings should be built out so full that after removing the excess the exact contour would be restored, whilst the surface of the gold would be sufficiently dense to permit the highest polish. This requisite at once banishes the matrix. Whether in the anterior or in the posterior teeth, superior or inferior, I like sand- paper for this work, and prefer the disk on the engine- mandrel to the strip, though both will be required to meet all cases. I believe the more common practice is to use the disk with the sand side facing away from the engine hand-piece which holds the mandrel. Occa- sionally such a position will be peremptorily needed. Ordinarily I recommend that it be placed exactly the other way. With the sand side facing the hand-piece, and sufficient practice to acquire dexterity, the operator will find that he can manage the greatest variety of fill- ings. I can reach and polish without other instrument the following : Anterior and posterior approximal surfaces of incisors, cuspids, bicus- pids, and first molars, and the posterior surfaces of second and third molars ; labial surfaces, especially including festoon cavities, and often the palatal surfaces. After the disk has been used a little so that it becomes pliable, I can trim a filling, shaping approximal angles, without flattening. Where the tooth is long, and wide at the crown, I can reach the gingival margin of the filling by pressing the disk against the adjacent tooth, which compels it to run as though con- caved. In many inaccessible places I compel the disk to accomplish my purpose by holding it against the part with a flat burnisher pressed 1 88 METHODS OF FILLING TEETH. against its reverse side. In fact, the disk on the engine in my hands is more useful than any other finishing appHance. I may say here that in spite of the undoubted ingenuity which has been displayed in the invention of disk-carriers, the best for all practical purposes is still the original simple screw-mandrel. Instead of using a screw- driver, however, the disk may be placed or removed by having the mandrel in the engine, and holding the disk whilst the engine is started quickly. After using a medium grade of disk for taking off the surplus mass of gold, follow with one made from the finest pouncing-paper. This will produce a good polish. Nevertheless, a higher luster still should be attained by use of a strip of chamois well chalked. For this the best material is what is known as " whiting." I do not like files, either between the teeth or on labial surfaces. In the former they are apt to leave flat planes, and in any event they make scratches, which must be removed finally with the sand-paper, so that the disk may as well be chosen at the outset. Occasionally a file may be needed for making sufficient space in which to revolve a disk or pass a strip ; still, even in these cases I prefer a saw, which, having no cutting sides, removes only the rough excrescences which prevent the ingress of the sand- paper. The approximal trimmer is a humane and valuable instrument. Where the cervical margin reaches to or passes the gum-margin, the over-build of gold should be removed carefully with the approximal trimmer rather than with a sand-paper strip or disk, either of which will so wound the gum that not only will it remain in a state of irritation for several days, but frequently recession is induced. This instrument is also essential for the finishing of festoon fillings. In these cases it will often be better to remove the dam as soon as the filling is placed, for the reason that the clamp interferes with the work. With care, a fine finish may be achieved without wounding the gum. This is, however, a difficult place to contend with. With the approximal trimmer remove the excess of gold carefully, even though that may mean slowly, per- fecting the gingival margin and working from the gum toward the incisive end of the tooth, thus avoiding wounding the gum and consequent hemorrhage. The gold trimmed to approximately proper proportions, resort to the smallest disks, placed on the mandrel as before directed. Placing the edge of the disk near the gum, slight pressure will cause it to bend, so that as it is revolved it finishes the surface of the gold, the edge of the disk if required even passing under the gum-margin without wounding it. A final polish may be- produced with the polishing-powders on soft-rubber disks, or in connection with wood points. The rubber cup. Fig. 200, is invalu- able. THE FINISHING OF FILLINGS. 1 89 In the crowns of bicuspids and molars, I like finishing burs and burnishers in the engine when the fillings are small. Where they are of medium or large size I use them first, for the reason that a more thoroughly dense surface is obtained by burnishing. But for a final finish I do not admire the irregular surface left by the burnisher. I therefore depend upon small fine corundums, Hindostan and Ar- kansas stones, finishing with pumice and chalk, used one after the other on the soft- rubber disk. Amalgam. — The same general rules of aiming at and obtaining a lustrous polish are to be observed with this much-abused material. The approximal trimmer, however, will not avail, and for this reason the gingival margin should be made as nearly perfect as possible whilst the material is yet plastic. The sand-paper disk will do much along this part of the approximal surface, but will not always reach the extreme gingival margin. Here a fine finishing file having a small end, somewhat similar to the approximal trimmer, will serve well, the final finish being given with a spatula cut from t^, ^ . Fig. 200. orange-wood, and used m ^KKk connection with the pol- w -,_. „,-,, ^j - _^ lilHlli k ishing-powders. In crown Tbbt-i ifiifi,,iiirT-— ,^^^^^^ ||HI|i| ^^' and large contour fillings, ^^ after using the rubber disk with pumice and then with chalk, nothing makes an amalgam filling so handsome as the use of the small engine brush- wheel, of mod- erate stiffness, used first with moistened pumice and then with dry chalk. I dis- miss this class of fillings resembling a mirror in color and luster, and they keep their handsome appearance a long time, remaining forever smooth, though getting dull in time. Oxyphosphate. — When used as a permanent filling, this material should be allowed to set thoroughly hard before any attempt is made to trim it to shape, and when shaped a final finish may be made with the pouncing-paper disk, followed by the chamois strip without chalk. The dam being still in place, the filling should be thoroughly coated with chloro-percha, which should be allowed to harden by the evaporation of the chloroform before the dam is removed. If this rule is properly observed, this film of chloro-percha will often be found upon the filling two weeks later. Thus the material has been protected from moisture until hardened to a density not otherwise attainable. G2dta-percha. — This material is trimmed to shape with warm bur- nishers, and then quickly hardened by applying cold water. After igo METHODS OF FILLING TEETH. this, if an examination shows that there is an overlap under the gum- margin, dip floss silk in chloroform, and slipping it between the teeth (supposing it to be an approximal cavity), move it back and forth. This will remove the excess without disturbing the filling, as might occur if the use of heated burnishers were essayed again. CHAPTER VIII. Methods of Filling the Canals of Pulpless Teeth— A Study of TooTH-RooTs— Methods of Gaining Access to and Preparing Canals— Methods of Cleansing Root-Canals— When and How to ^FiLL Root-Canals. '' Teeth are filled that they may be saved ; that is, a tooth which is attacked by caries is in danger of destruction and final loss, and a filling is inserted in the hope of saving it from this result. If a tooth which simply has a cavity in it is in a precarious condition, how much more must this be true where the pulp has died ? One might almost say that a tooth which is pulpless is half lost. Its future depends upon the insertion of a proper root-filling ; and where it receives unskillful attention in this direction, only a small chance exists of its long remaining a healthy member of the arch. The loss of the pulp is not in itself the cause of disaster, for pulp- less teeth may remain healthy and useful indefinitely. The trouble is that if the dead pulp be left in, its putrescence becomes a source of excitation which usually results in pericementitis, probably followed by alveolar =abscess. The remedy lies in the thorough removal of the pulp, the hygienic cleansing and sterilizing of the canal, and the insertion of a root- filling which will completely replace the pulp, mechanically filling the chamber. I may, then, at the outset take up a consideration of the obstacles which will hinder the thoroughness of root-filHng. There are skillful men, who are also reliable, who will unhesitatingly claim that they fill all roots to, or very nearly to, their apices. This would involve such treatment of the buccal roots of superior molars, and the mesial roots of inferior molars, which are usually admitted to be most diffi- cult. Other men will admit that they are not so successful, but feel assured that they can manage all anterior teeth. That any men prac- ticing dentistry have succeeded in completely filling the canals of all cases which they have undertaken, I do not believe. That they may believe that such success has been attained I do not doubt, and therefore I accept such statements as honestly intended, but erro- neous from the fact that the gentlemen have not considered teeth BIE THODS OF FILLING CANALS OF PULPLESS TEE TH. 1 9 1 except as they have dealt with them in the mouths of patients, under which circumstances failure to reach the apex may be undistinguish- able. A study of roots, out of the mouth, and an attempt to fill the canals, would materially alter the opinions of those who are so certain that they always reach the apex.* Nevertheless, I think that these men get nearer to the ideal root-filling than do those who are willing to say quickly, " That is as far as I dare to go," and so fill the canal without having made a conscientious effort to cleanse it. I will now consider the canals of various teeth. Central Incisors. — The superior central incisor is usually a single- rooted tooth, presenting a fairly straight canal. Nevertheless, it must always be borne in mind that the crown of a tooth is not necessarily a guide to the length, shape, or direction of its root. More true of the posterior regions, this axiom is also true of teeth in the anterior part of the jaw. Fig. 20 r represents a central incisor whose crown and root are about proportionate, whilst in Fig. 202 is seen another Fig. 201. Fig. 202. Fig. 203. Fig. 204. Fig. 205 central which has a larger crown and a shorter root. Such short, thick roots are by no means uncommon on central incisors. The point of interest here is, that supposing the dentist is cleansing the canal of a tooth having such a crown as shown in Fig. 202, measure- ment with a canal instrument might lead him to believe that he had not reached the end of the canal, whereas were he to attempt to go farther he would pass through the apex, forming an opening at the side of the true foramen. I think it may be safely stated that in ninety per cent, of tooth-canals there is a deviation from a straight line just in the foraminal region, so that a drilling instrument would, as I have said, be apt to pass out to one side rather than directly through the foramen. These artificially made openings are almost always mischievous, and the mischief is greater or more uncontrol- lable in proportion as the drill-hole is nearer the foramen and so more inaccessible than were it nearer the coronal end of the canal. I said that a central presents a fairly straight root and canal ; still, there are frequent cases where the root is twisted or curved, an example of which is shown in Fig. 203. In the illustration the palatal aspect of a central is given, and is chosen in preference to the 19- METHODS OF FILLING TEETH. labial, because of the line of approximate bifurcation seen from this view. This makes it possible that the canal within may be divided, the bifurcation of a pulp usually being coincident with that form of root. This figure also shows a distinct curve near the apex, and exhibits the danger that would accompany the free use of any style of drill that has a point allowing it to make forward cutting. The central in the inferior jaw is usually found with a broad, flattened root, which, viewed from the side, presents a concaved groove extend- ing the full length of the root. This groove is very significant, for it is the lateral wall of the canal, so that it follows that the pulp-canal is the narrowest diameter of the tooth. We must also note that these lateral walls are quite thin. If a canal-reamer were used which had a bur-head larger than this narrow diameter of the tooth, it would follow of necessity that this lateral wall would be punctured, so that it is not alone the forward cutting of a canal instrument which ofifers a danger of opening through the roots of teeth. It would rarely if ever be necessary to use a drill or ream.er in the lower incisors, because, as seen in Fig. 204, though the canal is flattened laterally, it is usually wide enough in the other direction to afford ample space for cleansing and subsequent filling. Lateral Incisors. — The roots of superior lateral incisors almost invariably terminate in a crook at the apex which curves posteriorly. In Fig. 205 is shown a curious example. Judging by the general direction of the crown, the course of the root could not be guessed at all. The root curves toward the median line of the mouth at a con- siderable angle, yet at the apex the rule above stated is found exempli- fied, there being a crook which turns posteriorly. It is probable that the root of this tooth was upright when in the alveolus, the crown appearing irregularly curved toward the centrals. Were it not dis- covered that this curve of the root existed, it is evident that were the root drilled, the instrument might emerge someivhere about half-way between the crown and root-end. Fig. 206 shows another lateral incisor, where we find a crown not much larger than in the last case, whereas the root is much longer. Again is seen the posterior crook at the extremity. An approximal view of this root would show also an apical curve toward the labial plate of the alveolus. The lateral incisors of the inferior jaw do not materially differ from the centrals, except that they are slightly larger. Cuspids. — The cuspid is usually the most readily filled of all pulp- less teeth. Ordinarily the canals are proportionately large and moderately straight, and one feels fairly satisfied that at least in this tooth the canal may be filled to the extremity. Yet take a handful of cuspids, and an examination of them out of the mouth will show so A STUDY OF TOOTH- ROOTS. 193 many crooked extremities, or ends that assume twists and curves, that a doubt is engendered, and one may well wonder whether even here perfect results are always attained. May it not be that because the canal-explorer reports that considerable length of canal has been reached, the operator decides that he must have come to the apex? May there not still be a crook beyond, which has not been touched by instruments, however fine? Compare Figs. 207 and 208. In both, the Fig. 206. Fig. 207. Fig. 208. Fig. 209. Fig. 210. crowns are about similar in size, yet how different the length of root. In Fig. 207 observe the crook which tips the root end almost at right angles. Look at Fig. 209, with its curved root and crooked end, and, drawing an imaginary line through the central axis of the crown, note where it would emerge through the side of the root were a drill to follow the same course. Fig. 210 shows a double-rooted cuspid, and it would not be difficult to imagine a dentist thoroughly cleansing and filling the labial canal, entirely neglecting the palatal, because of its small size and rarity. Bicuspids. — The first superior bicuspid brings us many problems in root-filling. Usually the canals are bifurcated, whether the roots are Fig. 2X2. Fig. 213. or not. Sometimes the canal will be confluent throughout, being con- nected by a narrow passage, as shown in the diagrammatic section in Fig. 211. Here a, a indicates the openings to the canals proper, whilst at b is seen a narrow passage connecting the two. It is this, passage which is a point of great interest. It is almost always present, at least in the pulp-chamber occupying the crown. It is safe to. enlarge it, thus completely connecting the two parts of the canal,, 13 194 METHODS OF FILLING TEETH. until the line of the tooth-neck is reached. Beyond this it becomes necessary to observe the greatest caution in proceeding, in order to determine how far such enlargement may be pursued, whether or not the canals are normally connected throughout, or whether they or the roots are bifurcated. In Fig. 212 is shown a first bicuspid wherein the canals are probably united in this way throughout, as I judge by holding the specimen up to the light so that the canals are indicated, and by the further fact that they emerge at a single foramen. Yet Fig. 214. Fig. 215. Fig. 216. Fig. 217. observe the curious distortion of the root, and it is plain that enlarge- ment within the canals would be a procedure requiring the utmost care, whilst complete root-filling would be of doubtful possibility. Fig. 213 shows us the palatal aspect of a bicuspid in which there appears a bad crook in the palatal root, which curve is present in the buccal root also, though in a less marked degree. Fig. 214 shows the buccal aspect of a bicuspid which has a similar crook, a second curvature appearing nearer to the apex. Fig. 215 is another bicus- pid, the curve here being near the end of the root and very pro- nounced in character. In any of these three teeth a root-canal drill would be a hazardous dependence, and as the contours of root-canals Fig. 218. Fig. 219. Fig. 220. Fig. 221. cannot be known from the appearance of the crowns, it becomes necessary to make thorough exploration before attempting to use any engine instrument, especially those having long slender shafts. Fig. 216 shows a tooth the roots of which are united, a deep groove, however, indicating that the canals may be distinct, which is shown to be true when examined by transmitted light. Fig. 217 is of the same class, the bifurcation of the roots in the immediate vicinity of the foramen being more distinct. Fig. 218 A STUDY OF TOOTH-ROOTS. 195 gives us a tooth practically similar to that depicted in Fig. 216, Here, however, we have a ground section which brings us to a clinical feature of tremendous importance. A portion of the side of the tooth has been removed with great care, so that no portion of the canal shall be obliterated, the stone not passing beyond the center line. The pulp-chamber is clearly seen, as well as the bifurcation of the canals in what externally seems to be a single-rooted tooth. But in the vicinity of the apex the track of the canal can only be seen by examining with a magnifying glass, and even then it seems to be closed as though ossified. Of course it is not, and in life a fine thread of living pulp passed through this foramen. But this passage is so fine that the eye, even aided with a magnifying glass, cannot discern that it exists. Moreover, the finest canal bristle cannot be made to penetrate this passage, which, though open, appears closed. If this be true with the specimen in the hand, who can say that in the mouth he would have been able not only to explore this, but to properly fill it subsequently ? It may be claimed that this canal could Fig. 222. Fig. 223. Fig. 224. Fig. 225. be enlarged with chemical agents. That will be discussed later. At this point we may simply consider it a barrier impassable to mechanical devices, yet in reality a true open passage. Moreover, this condition, as indicated here by a single specimen, is not rare. Indeed, in many of the tortuous canals of molars this fine, impassable canal is far from uncommon. This should not be disputed by anyone until he has made sections of at least a hundred twisted or con- stricted molar roots. That such tiny passageways may contain living matter need cause no one to wonder. There are beetles so small that the entomological collector finds them by using the finest meshed sieve and sifting out a handful of dirt, the beetles remaining with the larger debris, but not to be found until the collector is in his den and seeks them with a magnifying glass. Yet these tiny creatures are highly organized, and have powerful muscles with which to move their limbs. The power of motion is transmitted to these muscles by nerve-fibers so small that a dozen of them twisted into a rope could occupy one of our invisible root-canals. Fig. 219 brings us to the opposite extreme. Here we see a tooth 196 METHODS OF FILLING TEETH. from a child. The foramen is wide open, the root not yet being fully- formed. In Fig. 220 we see a similar tooth ground to expose the canal, which is very wide throughout, the foramen being as wide as any part. Should a pulp die in a tooth of this character, great skill is requisite in filling the canal to avoid having any of the root-filling extend beyond the apex, in which case an abscess would not be an improbable sequence. Fig. 221 is introduced to show that, unlike the laterals, there is no rule which applies to the direction of the possibly existent crook. Here the apex curves toward the buccal plate of the process, while in Fig. 215 the curve is postero-approxi- mally ; in Fig. 217 the deflection is toward the palatal side. Fig. 221, though single-rooted, has two distinct canals and two foramina. Fig. 226. Fig. 227. Fig. 228. Fig. 229. Fig. 230. The buccal canal would be a serious problem in filling, being attenu- ated as well as badly curved. Allusion has been made (Fig. 211, <^) to a narrow passage which often connects the true canals in double-rooted bicuspids. Where this exists it becomes highly important to be able to decide to what depth it may be widened. A study of Figs. 222, 223, 224, 225, 226, and 227 will indicate the varying extent to which bifurcated canals may be connected with true bifurcation of the roots. Fig. 228 represents a root the crown of which has been lost. Here we have a trifurcation which produces three canals, and it is evident that the two smaller, especially the crooked one, would be troublesome. The perforation of a bicuspid canal, at the point of bifurcation, with resultant hemorrhage and subsequent complications, may always be avoided, if the operator will approach every canal as though certain that the bifurcation exists. If he should discover later that the canals are confluent, or that the tooth is single-rooted, at least he will have attained his result without accident. If, on the contrary, he should overlook the possibility that there might be a bifurcation very near the crown (as in Fig. 224), he will some day discover this fact by having his engine bur plunge through the root into the alveolus beyond, with more or less disastrous consequences. The second bicuspid is usually single-rooted, though even here A STUDY OF TOOTH-ROOrS. 197 two caaals may be distinctly existent. Fig's. 229 and 230 indicate that similar crowns may have roots quite dissimilar as to shape and length. The latter has a tiny but distinct right-angled crook at the foramen. Figs. 231, 232, 233, 234, 235, and 236 furnish a variety of supe- rior second bicuspids which, at a glance, teaches that the crown is no index to the length or shape of the root. The crown of Fig. 231 is as large as that of Fig. 235, yet the roots are dissimilar. One is twice as long as the other, and whereas in one the curvature is toward the palate, in the other the principal deflection is toward the buccal plate. Fig. 234 shows us the largest crown, but look at the dispro- portionate root. Fig. 233, apparently a single root, has two canals, as have also Figs. 235 and 236. Fig. 231. Fig. 232. Fig. 233. Fig. 234. Fig. 235. Fig. 236. Inferior bicuspids are often difficult because of the length and attenuation of their roots. I do not mean that this is always so, yet Fig; 237, with its small crown and long, narrow root, is a fair ex- ample of a lower bicuspid, while Fig. 238 adds to the difficulties of the situation by possessing an extensive crook. Fig. 237. Fig. 238. Fig. 239. Fig. 240. Figs. 239 and 240 are two first bicuspids from the lower jaw, ex- tracted from the same mouth. They are beautiful examples of an extreme but far from rare type. I have another pair showing exactly similar contours. The point of interest here is that the obstacle which would interfere with the proper treatment of the roots lies not in the roots themselves, which in these specimens are very simple, but is rather due to what I may term the pose of the crown. Teeth of this 198 METHODS OF FILLING TEETH. type are often found, apparently crowded out of the arch, and pro- truding lingually. Of course normally shaped teeth are occasionally crowded out of alignment, but often the seeming irregularity is mainly due to the malposition of the crown in relation to the root. Supposing that these teeth were in the mouth, the roots occupying the normal upright position in the bony socket, but the crown tipping toward the tongue, it is evident that the best approach to the pulp- canal, if access was necessary, would be through a cavity drilled in the buccal face of the tooth, rather than through the masticating sur- face as is customary. Where the original cavity is in the approximal surface, it is often better not to enlarge it, as would be the course elsewhere, cutting through the masticating surface, but rather to make a small aperture in the buccal face of the tooth, thus entering the canal directly, and through an opening more readily managed than one in the masticating surface. Of course, before adopting this method, it is highly essential that the true direction of the root be known, but this is not difficult. Observe the plane of the buccal sur- face of the tooth (Fig. 239), and if the root follows the direction in- dicated by the crown, then there should be a pronounced bulge of bone just below the corner of the mouth. Fig. 241. Fig. 242. Fig. 243. Fig. 244. Fig. 245. Molars. — The buccal roots of the superior molars present probably the most difficult problems in the whole range of root-canal fillings. To the prominent gentlemen who have repeatedly asserted that they can fill any buccal root, I offer the pair exhibited in Fig. 241 for study and consideration. To these same gentlemen, and to those who are sure that at least they can fill the palatal root, I offer Fig. 242. Sup- posing for an instant that they succeed in overcoming the obstacles offered by the crook at the end of each of these roots, I would still ask how to fill the canal of the concrescent tooth seen attached to the palatal root. Lest it be said that such conditions are" quite rare, I introduce Fig. 243, wherein the buccal roots are almost identical to those in Fig. 241. The original of Fig. 242 was a specimen which I had never seen in the mouth, but since the publication of the first edition of this A STUDY OF TOOTH-ROOTS. 199 work I had a case pass through my hands in which the recollection of this anomaly was most advantageous. A molar came to me in which an old amalgam filling was leaking, and recurrent caries had reached the pulp, making devitalization necessary. In cleansing the canals I was surprised to find that my bristle penetrated so slightly into the palatal root, and I was further astonished to find the opening of the canal so near the margin of the cavity, when I suddenly re- called Fig. 242. Further exploration disclosed the fact that I had not yet opened into the true palatal canal, which, when discovered, was of normal extent The short extra canal was unquestionably of the nature of that indicated in the illustration. Fig. 244 is from a most remarkable specimen. One of the buccal roots has become fused with the palatal. The figure shows the an- tero-approximal aspect of the tooth, and the canal of the missing Fig. 246. Fig. 247. Fig. 248. Fig. 249. Fig. 250. buccal root terminates in a foramen at the side of the palatal root just above the bifurcation. The posterior buccal root is present, but all that portion above the line of bifurcation would defy all effort to cleanse or fill, not alone because of its tortuosity and attenuation, but because the opacity, as seen by transmitted light, indicates to me that it has one of those invisible impassable root-canals described in con- nection with bicuspids, It is not uncommon, when cleansing the canals of upper molars, to have tKe bristle pass 'into an opening apparently just at the bifurcation of the three normal roots. Examination of specimens out of the mouth proves that a fourth root in this situation is far from rare. Fig. 245 is a well-marked case of this character. Once the anomaly is recognized, there would be no difficulty with such a root as this. But many would feel content with filling three canals, and seek no other. Suspicion should be aroused whenever this central canal does not curve toward the buccal plate of the process. Fig. 246 is from another such specimen, one of the normal roots being broken off, so that the one in the center is the fourth root under discussion. Fig. 247 is from still another specimen. Fig. 248 be- longs to the same class, though here the extra root is fused with one of the buccal roots, which consequently has two canals and two 200 METHODS OF FILLING TEETH. foramina. Fig. 249 also has the little fourth root, while the crook in the palatal root warns us that all palatal roots are not necessarily simple, a fact further emphasized by Fig. 250. Here the palatal root has a magnificent curve, while the two buccal roots are united at their apices, ending in one foramen, though otherwise distinct throughout. In Fig. 251 we have excessively long roots, the two buccal being fused but having distinct canals, that in the anterior, and therefore least accessible, being tortuous. Fig. 252, with its curved and hooked buccal roots, one being of the broad, thin variety, offers an alluring prospect to those who are really fond of hard work. Fig. 253 shows how attenuated a long buccal root may be, and the variation in the length of the two buccal roots indicates how certainly we may know when filling roots in the mouth that we have reached the ends, espe- cially when the length of one root is depended upon as a guide to the length of its neighbor. In the lower jaw it is usually the anterior molar root that is trouble- some. Ordinarily we expect single canals, though in the anterior root the canals are often bifurcated. In Fig. 254 is a specimen Fig. 251. Fig. 252. Fig. 253. Fig. 254. Fig. 255. wherein the posterior roots are completely bifurcated, one oiTering so bad a crook that it would have been quite difficult to fill it. In the anterior root two distinct canals exist, though the root is single. This tooth and its fellow, which is exactly similar to it, I removed from the mouth of a negro boy. They are sixth-year molars. This tendency to complete bifurcation is more common in the posterior root. I have a number of specimens which show the double root posteriorly and the single root anteriorly, being similar in general appearance to Fig. 254, the extra root in all being at the posterior lingual angle. In Fig. 255, however, we see a specimen which indicates that the lower like the upper may have an additional appendage between the normal roots, just at the bifurcation. In this instance no true canal- appears in the appendage, but in other instances I have known a fila- ment of the pulp to dip down into such an extra root, diminutive though it be. A STUDY OF rOOTH-ROOTS. 20I The wisdom-teeth {denies sapientiee) are so commonly misshapen that it is easier to get specimens with distorted roots than with regu- larly formed ones. They are also so generally condemned to the for- ceps that root-filling is seldom practiced. Yet occasionally it is best to make the effort to save such teeth, and I may be pardoned for introducing one or two illustrations, that the student may get an idea of what he may have to contend with. Fig. 256, from the upper jaw, would be a puzzle, whilst Fig. 257, also an upper tooth, would be equally so, with its three roots all curved, the palatal one forming almost a bow. Fig. 258 is a fair mate to it from the lower jaw, whilst Fig. 259 indicates that we cannot always be sure that a wisdom-tooth is short-rooted. The length of the roots in this case would be almost as great an obstacle to thorough cleansing and filling, as would the curve of the preceding specimen. Lest it be argued that I have selected extreme cases for illustrating the difficulties to be contended with in filling roots, I must here reply to such a proposition. In the first place, such conditions are not very Fig. 256. Fig. 257. Fig. 258. Fig. 259. unusual or difficult to find. That this is true is made plain by the statement that the specimens used here, with a i^^fi exceptions, were obtained through the kindness of Dr. Hasbrouck, who allowed me to look through a small lot of teeth extracted in his office. The speci- mens were selected in about ten minutes. I could have chosen in many instances much more remarkable distortions, but did not think it necessary. I could readily have enlarged the number tenfold, but that also would have been of no advantage. Of wisdom-teeth there was the greatest assortment, possibly because more of these are sacri- fied than any other one tooth. The only real rarity among the fore- going illustrations is the two-rooted cuspid. Yet I once remoA-ed such a tooth from a young lady, and on the same day extracted a first bicuspid for her mother which had three roots much more marked than those shown in Fig. 228. Again, I may defend this exhibit by the argument that we cannot learn to anticipate possible difficulties by a study of simple conditions. 202 METHODS OF FILLING TEETH. It is only by an appreciation of the fact that the roots of teeth are of all manner of shapes, and that the crown is not a sure indication of what we may meet in exploring the roots, that we can hope to exercise that precaution and attain that skill which will make it possible for us to reach that point where we can even fool ourselves into the belief that we are filling all roots to the apices. Yet it is essential that, how- ever great the obstacles may be, we should endeavor to do this ; and I will now try to explain the best modes of so doing. Methods of Gaining Access to and Preparing Root-Canals. Before a root-canal can be properly filled, it must be thoroughly cleansed and made accessible for the material which is to be used. Admitting that many conditions might occur, as has been indicated by the foregoing illustrations, where it would be impossible or most difficult to fill some canals, it yet is true that many of these can be approximately well cared for where proper methods are employed, and patience and skill are brought to bear upon the obstacles. Con- versely, many simple canals are often improperly filled through lack of skill or from laziness. The first object is to attain free access to the canal. Central Incisors. — The central incisor having ordinarily a straight canal, usually of fairly large size, should offer few obstacles to proper treatment. The cavity of decay must occur either upon one approxi- mal side, upon the palatal, or upon the labial surface. Where it is upon the palatal, the canal is readily entered from that point. When upon the labial, unless the cavity is well extended toward the incisive edge, so that it is not difficult to get directly into the canal, I should make a new opening at the palatal surface. Where the approximal cavity is small, I should do the same ; but where large, a simple extension of the palatal border of the cavity should be made until a nerve-canal instrument could be made to enter the canal without bending. Thus it is seen that I advocate entering the central incisor from the palatal surface. This would also be" the case where a pulp had died from traumatic disturbance, and, no cavity being present, a drill should be passed in at the point indicated. The enamel being un- broken, and therefore resistant to the drill, it is well with a small corundum point to grind off" the polished surface, after which the drill will cut readily. The drill should be sharp and small, making a nar- row opening to the pulp-chamber, which is afterward enlarged with fissure-burs. A cone bur also does this rapidly. Fig. 260 is dia- grammatic, and indicates the relation between the usual opening of this character and the pulp-canal. Through such an opening it PREPARING ROOT-CANALS. 203 Fig. 260. Fig. 261. /^ might be possible to pass a flexible broach and remove the pulp, but it is evident that to attempt to fill the root might result in im- proper treatment of that part between the opening, a, and the end of the canal at b. Consequently, my custom is to insert a sharp rose bur through the opening as far as the wall of the canal, and then bring it for- ward toward b, removing the part intervening. Even with the opening thus enlarged, ready access will often be impeded because of the angle at c, so that with a bur I effect further en- largement, till the canal, fully opened, appears as seen in Fig. 261. Where these canals are large enough, they need no further reaming than at the aperture ; but where they are dis- torted, attenuated, or partly stopped up because of deposits of secondary dentine along the walls, I use the reamer as far as possible. As the subject of reaming or not reaming canals is one which is much discussed and disputed, and as seemingly equal authorities will most positively adopt one side to the entire exclusion of the other, I may as well here take up this point and give my own views, based upon my experience. The chief objections to using a reamer to enlarge a canal throughout are, first, the danger of making an aperture through the side of the root or near its apex ; secondly, danger of crowding debris forward, so that even where it does not pass through the root, carrying possible infection into the territory beyond, it may become packed into the canal itself, limiting further progress, and so after all preventing the proper drilling or filling of the canal ; lastly, the drill may be broken off and remain in the root. The advocates of reaming all canals say that by enlarging they insure better filling, and that in teeth where pulps have been long dead the canal-walls are probably in a partly softened and certainly septic condition. In these teeth is it not better to remove this, than to endeavor to disinfect or to sterilize it ? Extremists are not good teachers. The man who reams out every canal to its apex is as unworthy of a followiyig as the other man who can fill all canals without having a reamer in his office. The true method is to have a good assortment of reamers, to know how, when, and where to use them, and to use them with skill and caution that will assure success. I hope that I belong to this last class, and 204 METHODS OF FILLING TEETH. Fig. 262. Fig. at least I shall describe my methods of using reamers as I go along, indicating where obstacles are to be met and how to avoid them. I have been asked, ' ' Can you drill around a curve ?' ' The answer is that it can be done, and many times must be done. Suppose that I am using a reamer, and I feel a resistant spring to my instrument, yet do not strike the end against anything that would indicate that I have reached the region of the foramen. I know at once that the canal has a central curve in it, and that as soon as the head of the reamer reaches this place, the curve of the wall diverting the drill-head, makes a tension upon the flexible shaft so that I get a response which I have described as feeling a resistant spring. This is always a danger signal. Force the instrument a bit farther, and the shaft will snap, breaking off the drill-head. Worse thau this, the broken piece will be at such an angle that it cannot be removed. This is made plainer by Diagram 262, where the drill-head is seen at a, in a position that makes its removal impossible without very great enlargement of the cavity. Where this happens, it is evident that all the canal beyond must remain unfilled. Consequently, as soon as the springy resistance is noticed the reamer must be removed. If a small- sized Gates- Glidden drill has been used, the largest size may be chosen to replace it. This, having a stouter shaft, may have the power necessary to success- fully resist the tension while the drill- head cuts away the bulging wall at b. If it was the largest-size drill that was in use in the first instance, it must be replaced by a fissure-bur of small size, with which the upper bulge at c could be removed, after which the large Glid- den drill will readily remove the obstacle at b. This accomplished by either method, the drill can be advanced as far as d, beyond which it cannot be carried. The canal would now present as in Diagram 263. During this work there will be the danger already noted of clogging up by pushing forward debris. This may and must be avoided. It results mainly from the desire to work too rapidly, which, by throwing back a great amount of debris, renders it difficult to with- draw the drill. It is compelled to cut its way through, and so leaves PREPARING ROOT-CANALS. 205 within the canal some of the chips, which at the next entrance of the drill are pushed forward and packed into the extremity. The proper method is to avoid this, first by frequently withdrawing the drill, cutting only a little at a time, and secondly by using a cleanser every time the drill is removed, with which the debris is easily loosened so that it is withdrawn or may be blown out with the air syringe. The continued use of a drill of the Gates-Glidden type cannot open a hole by forward cutting, since it has a safe end. It could make an aperture by lateral cutting, however, if used where the canal has flattened sides and thin walls. This is most common in lower incisors and in first bicuspids, so that these canals should be most carefully scrutinized before the risk of using a drill is taken. Even where it is deemed safe to use it, by every precaution we should be upon the alert to avoid the disaster. The patient should most certainly give a sign of pain before the opening could be actually formed, for the heat from the friction would be conveyed through the thinning wall, causing a response. Thus it is a safe rule to withdraw a drill upon the slightest evidence that it causes pain. In Diagram 263 we have the canal partly prepared ; but as the curve at the extremity prevented the further use of the drill, what are we to do ? What has been gained, since it is after all this very part of the root which we should most certainly fill ? The reply is, first, we have lost nothing, for if it were possible, as some claim, to fill this curved part without enlargement of the rest of the canal, we, assuredly can do so now, with greater access. In fact, we can more certainly accomplish it. The use of broaches will indicate the nature of the curve, for as it is withdrawn now, the curve at its extremity, where it followed the bend of the root, will not be bent back, the en- larged canal allowing it to be freely removed. Lateral Incisors. — Lateral incisors are practically the same as cen- trals. They are, however, smaller, require smaller instruments and greater care, and are more often found with a curved apex. A seem- ingly straight canal in this tooth, therefore, is to be accepted with greater doubt than where dealing with the central. Ctcspids. — The same rules apply to cuspids as to the incisors. Whilst it is true that these are sometimes short-rooted teeth, ordi- narily they have quite long roots, so that the dentist must make a careful examination when his canal explorers pass but a short dis- tance into the canal of a tooth having a large crown. Where the root is really short, the canal is usually large, the root being thick. Thus it will not be difficult to determine that an abnormal condition is at hand. There Is not often much danger of penetrating this root with a Gates-Glidden drill, but the end may sometimes be suddenly attenuated, which will also be the case in the canal, so that the drill 2o6 METHODS OF FILLING TEETli. may seem to be stopped by the apex of the root, whereas in reality it is simply that the canal hag suddenly grown so much smaller that the tip of the drill will not enter it sufficiently to allow the blades behind it an opportunity to cut and so enlarge it. An examination, how- ever, with a fine instrument after the careful removal of debris will disclose the fact that the canal continues farther. Bicuspids. — Generally the bicuspids may be opened for access to the canal either by deepening the crown cavity, or, where it is approximal decay which is present, an extension into the sulcus attains the desired end. In lower teeth, however, this is sometimes troublesome, as will be more fully explained shortly. Where in the upper jaw the cavity is at the neck of the tooth, a new entrance to the canal should be made by entering at the sulcus. Where a tooth, well filled with gold approximally, presents needing to have a canal opened, it will be unwise to remove the filling, as to drill through the crown will serve the purpose adequately and save refilling a difficult cavity. In the first bicuspid all the peculiarities of form are to be borne constantly in mind, and procedure should be slow and careful. Partial cleansing may disclose the fact that the coronal end of the canal is as represented in Fig. 211. The next point will be to determine just how deep the communicating passage b extends, and therefore how far it will be safe to attempt thorough connection of the two canals, for as two canals they should always be treated at the outset. In a few cases it will be possible to unite them throughout. Most often it will be safe to use a rose bur freely as far as the neck of the tooth. Beyond that explorations should be made with fine broaches, passed up one canal and then forced across into the other, where the passage exists. This will prove a guide, but stiff'-shanked burs must be discarded for working farther up in the canals, a slender Glidden drill serving better, because, whilst resistant enough to clear out and enlarge any passage which may exist, it will be found difficult with such a tool to cut through solid material. Where the rose bur or fissure-bur is recklessly used for this place, the inevitable result will be that sooner or later the dentist will make an opening near the beginning of the bifurcation of a double-rooted tooth, or even in one that has only bifurcation of the canals, the roots being coalescent, as in Fig. 216. The palatal canal will not be so difficult to cleanse as the labial, and in this latter, drills are to be used with the utmost caution if employed at all. The position of the patient and the pose of the tooth will generally be such that in forcing the drill into the labial canal it will necessarily bend, and to revolve a slender steel shank under such circumstances is to invite a fracture On the other hand, the drill will be more easily used after the coronal PREPARING ROOT-CANALS. 207 end of the canal has been thoroughly enlarged, for the reason that, having more space in which "to play," it will be less likely to bend. Sometimes the cavity in the crown itself may be enlarged, so that the drill will more directly enter the canal. When this can, it should be done. The treatment of curved extremities is the same as with the anterior teeth. The second bicuspid in the superior jaw is usually a single-rooted tooth. Nevertheless, here also the coronal opening will frequently be as in Fig. 211, and once more the narrow connecting passage at b becomes a point for study. This root, though single, is generally broad and flattened, and viewed out of the mouth often has the pecu- liarity attributed to lower incisors, there being a depressed groove corresponding with the center of the inner canal. Thus it is seen that throughout the canal the walls on either side, corresponding with b in the diagram, are the thinnest part of the tooth. I unite the two broader parts of the canal in a somewhat peculiar way. I use the Glidden drills as though there were two canals, exchanging to larger and larger drills until the two sides are as thoroughly cleansed as possible. This done, I take the smallest of the Glidden set, and, beginning at the coronal extremity of the canal, I pass the drill from one side of the canal through the narrow passage to the other. This is carefully repeated, passing higher and higher up the extent of the canal, until I either clear it throughout or else receive some inti- mation that it would be unwise to proceed further, — for it must never be forgotten that this tooth also may be bifurcated, at least near the extremity. The least signal of pain from the patient makes it wise to stop work. The lower bicuspids are often peculiarly difficult because they may be in some abnormal position, the most common and troublesome of which is a tipping inward, so that the labial surface is really partly occluding with the upper teeth. It is plain that in such a pose nothing would be gained by opening through the crown with the hope of using a Glidden drill. Where the cavity is in an approximal surface, however, such extension is often necessary even for the use of a broach, and occasionally the Pettit reamer may be used to advantage. Where the cavity is approximal, but near the gum only, or where it is similarly situated at the labial side, extension must be made along the posterior approximal angle toward, but not necessarily into, the crown. Molars. — Superior molars having approximal cavities are made accessible by cutting through to the crown. When the cavity occurs elsewhere, but not in the masticating surface, the canals are to be reached not through the original cavity, but through a special open- ing through the crown made for the purpose. The thorough opening of a pulp-chamber will often require the sacrifice of considerable 2o8 METHODS OF FILLING TEETH. Fig. 264. Fig. 265. tooth-substance ; but this, though a pity, is unavoidable. No senti- mental ideas should tempt the dentist to hesitate to make the opening complete. Where the original cavity is at the posterior approximal surface, some difficulty will be met in cutting through the crown far enough to gain access to the anterior buccal root. The easiest method, and one which will save much distress to the patient, as well as time and labor for the operator, is as follows : With a sharp spear-drill, drill a hole straight to the pulp-chamber through the anterior sulcus. The condition at this point is shown diagrammatically at Fig. 264, which is a section through a molar showing the buccal roots. The approx- imal cavity and pulp-exposure are seen at (2, and the new- drilled hole at b. The next step is to insert a sharp fissure-bur in this hole at b, when, using ^ as a fulcrum, and slowly tipping the instrument as it cuts, a passage is made through the crown with comparative ease. It must be observed here that we have two advantages by this method. First, by cutting from below upward, the enamel is approached from the dentinal side, which is always easier than to attempt to cut enamel from its outer surface. Second, by using the point c as a ful- crum much less force need be ex- erted, and that, having a ten- dency to lift the tooth from its socket, is less painful than the reverse would be. Moreover, there is less danger of having the tool slip when cutting in a hole, than when the effort is made to cut from the approximal surface directly through the crown. This groove being cut, the presentment from the coronal aspect is as shown in Fig. 265. The next step is to choose a large rose bur, and, passing it in at the posterior opening a, bring it forward, cut- ■ ting away the dentine at both sides freely, . thus undermining the enamel, which latter may then be removed with a chisel. To those who have not essayed this method a close study of the different steps is advised, for by it otherwise diffi- cult and extensive removals of very dense tooth-structure are made moderately easy. «- METHODS OF CLEANSING ROOT-CANALS. 209 Where the cavity is at the anterior approximal surface, the pulp-chamber must be entered with large rose burs, and then, using the anterior adjacent tooth as the fulcrum, the procedure is much the same as before, the enamel being undermined from the dentinal side, and then cut away with chisels. Practically the same rules hold with the lower molars. Here, as is often the case where the pulp is exposed at the buccal cavity, a drill-hole is made as before in the anterior end of the sulcus until the chamber is entered, after which the entire procedure is as though there were no buccal cavity, except where the latter is so large that it is necessary to unite it with the new crown cavity. Methods of Cleansing Root-Canals. Ready access having been obtained, the next step is to thoroughly cleanse the pulp-canals. A description of methods which are ser- viceable in the most intricate cases will sufficiently indicate the line of procedure in less difficult Fig. 266. Fig. 267. situations. The great prerequisite is the Donaldson canal- cleanser, Figs. 266 and 267. This instrument radically differs from what is commonly known as a "nerve-broach." The latter was primarily intended for the removal of pulps, and is of little if any service for other purposes. On the contrary, while the Donaldson instrument may be utilized for removal of pulps, its chief value is in cleansing canals, especially the attenuated canals in tortuous roots of molars. An examination of Fig. 266, in which the instrument is shown magnified, will dis-. close the fact that the barbing of the wire is quite different from ordinary broaches. In the old style broach, the barb was cut resembling the barb of a fish-hook, being a long,' slender, sharp point. Rotation or twist closes the barbs, injuring the instrument so that it is never as perfect after use as when new. The Donaldson cleanser is differently constructed ; the wire is round, and the barbs cut to a slight depth, only turning up what may be likened to a round-edged hoe ; moreover, these barbs are rigid, and can neither be twisted nor bent back to place against the shaft. Besides, the wire is barbed on all sides so that, being ar- ranged spirally around the shaft, the instrument may be carefully screwed into a canal, and then, being withdrawn, the hoe-shaped blades or barbs act as scrapers and cleanse the canal on all sides. Of equal or even greater service is the Donaldson bristle, unbarbed. This is made of piano-wire drawn fine, and may be forced into very 14 2IO METHODS OF FILLING TEETH. Fig attenuated and tortuous canals. In fact I may erect the dogma, "Where the Donaldson bristle will not penetrate, no root-filling is required. ' ' These unbarbed bristles are to be used with the preparation of Sodium and Potassium. This is fiir- nished in small tube-like bot- tles, the mixture resembling a soft amalgam, and being covered with a solid layer of paraffine. To reach the mixture an .instrument is carefully passed ^through the paraffine, thus forming a small hole through which the bristle may be plunged into the Sodium and Potassium mixture. The bristle should be thoroughly roughened by running a coarse corundum over its surface, after which it will readily take up the right proportion of the So- dium and Potassium mixture to be used in the canal. The rubber-dam being in position and free access to the canals having been ob- Itained, let us suppose that the buccal canals of an upper molar prove to be so minute that the bristle scarcely dis- covers the openings. A minute three-cornered ream- er, made from a broken Gates-Glidden drill, is placed in the right- angle hand- piece and the engine re- volved rapidly. The point of the reamer is then gently insinuated into the mouth of the canal, very little pressure being used. Frequently this hair-like reamer will open quite a passageway, but it must be thoroughly understood that it is not wise to attempt to reach far into the root with this delicate, easily-broken instrument. The object is merely to open up as far as METHODS OF CLEANSING ROOT-CANALS 21 1 may be done in perfect safety, and this will almost invariably be suf- ficient for further progress with the bristle. The reamer is then laid aside and as large a bristle as can be used is selected, and it should be short and stout enough to withstand considerable pressure. The bristle, roughened with the corundum as before described, is dipped into the Sodium and Potassium preparation, and coated with this valuable agent is passed into the canal and twisted slowly and firmly toward the end. This repeated once or twice will gain some head- way, whereupon the canal should be thoroughly washed out with a one to five hundred solution of bichloride of mercury in hydrogen peroxide, used in a powerful syringe having a gold or platinum needle, Fig. 268. Frequently (especially in the presence of septic pulp-tissue) this forcible injection will extrude stringy masses re- sembling soft soap. All such debris having been washed out, a smaller bristle is selected and the same method repeated, and this process is pursued until the operator is convinced that further advance toward the apex is impossible, or until the foramen is reached, which will be no uncommon result. It is undoubtedly true that many root- canals are so minute, or so obliterated, that neither mechanical methods nor chemical agents make it possible to reach the apex {vide illustrations and previous text). Fortunately, if such canals are cleansed as far as possible, using the word possible in its most rigid sense, there will seldom be reason for mental anxiety as to the future health of the tooth. On the other hand, unfortunately, the fact that there are roots which cannot be explored to their foramina is utilized by many as a balm to the conscience when roots are neglected which another more con- scienfious or. more skillful man could cleanse and fill from apex to crown. A case from practice may be cited, as instructive of what is the final possibility in root-canal cleansing and what the limit which even skill- ful men place upon their capabilities. A patient placed himself in my care for the treatment of a lower molar, which he said had been "treated and filled seven times, and has never been comfortable." There was no history of abscess ; no one of the seven dentists had discovered pus ; but all had unfilled the tooth, undoing the prede- cessor's work, unfiUing and refilling the roots. I did likewise, re- moving a large, handsome gold filling from the crown, a substantial layer of oxyphosphate from below, and finally gutta-percha from anterior and posterior canals. In these two canals the root-fillings were easily removed because the depth was inconsiderable, the bottoms of the canals, as far as they had been opened, being discernible to the eye. To relate what I did in detail would be but a reiteration of the above-described processes. I will only state that I gave that tooth 212 METHODS OF FILLING TEETH. four hours' treatment, but I reached the apices of four canals, as was convincingly proven by the fact that pus rose in each. The time mentioned was not occupied at a single sitting, four visits having been made before all the canals were thoroughly cleansed. This abscess without fistula having been thus discovered, and the canals being fully cleansed, the disease was readily cured by antiseptic measures and the tooth refilled. Aside from pecuniary recompense in such a case, there is full compensation in the consciousness of having passed beyond the limit of procedure set up by several gentle- men of skill, and such a success is an incentive and a spur when treating other roots which at first seem to be inaccessible. When and How to Fill Root-Canals, In discussing the actual filling of root-canals, it is essential to con- sider, at one and the same time, the condition of the tooth and the method of filling its canal ; for despite the fact that many skilled opera- tors have but a single method of treating all roots, I deem it wiser to be guided somewhat by the state of health presented. Before proceeding, however, I will allude to some of the various materials which have been largely recommended, and comment upon them. Gold. — Gold at one time was counted the only true material for fining a canal. If the tooth needed gold in the cavity, it also needed this precious metal in the root. The method adopted was to twist a rope of foil stiff enough to allow of its being forced into the canal, and yet soft enough so that it could be condensed thereafter. The method condemns itself, for it is apparent with but a moment' s, con- sideration that wherever the foramen was large the rope would be forced through, with the probability of causing future irritation and abscess. This is true of other materials, but in a less degree because of their plasticity. Lest some may claim that I am exaggerating this danger, I may say that I have frequently, in earlier years of practice, removed abscessed roots, finding gold projecting beyond the foramina. Lead. — Lead has been used considerably, and by some it is claimed that it exerts a therapeutic effect. Just how this is accomplished has never been satisfactorily explained to me, and I doubt its truth. It is used in a single cone, trimmed to shape with the knife, and driven into the root. The same accident of passing through the canal may occur, and again it may be wedged into the upper part of the canal without reaching and filling the foraminal end. Wood. — Within recent years it has been taught by some that a most excellent way of filling a root- canal is to trim the end of a stick of orange or other wood, and after dipping it into some germicide FILLING OF ROOT-CANALS. 213 drive it into the canal, leaving it there. I cannot too strongly con- demn this method. Once more we find the material driven through the canal end ; and even where this does not happen, abscesses are common. I have seen a very large number of them. Then, when it is imperative to remove the canal-filling, the operation will prove most trying. The wood splinters, so that it cannot be withdrawn with forceps, tweezers, or pliers, whilst a drill simply tears it to shreds which are still more difficult of removal. Cotton. — Next to wood, I think this the most despicable thing to leave permanently within a tooth-root. I have heard men tell of removing cotton which had been in teeth for many years, and which had kept the canals sweet, there being a noticeable odor of carbolic acid still present. I always think that the odor is probably due to the fact that the dentist uses that remedy freely, so that he can smell it whenever his own fingers get near to his nostrils. I have removed a great many cotton root-fillings, and have noticed distinct odors in nearly all cases, but they have been far from sweet. They have been of that order which is associated with the dead and the putrescent. In some cases I have unearthed odors which were as vile as anything that had ever assailed my olfactories. I will introduce here a case from the practice of a dental friend which is instructive and suggest- ive. A physician called upon him, bringing his wife, concerning whose condition the dentist was consulted. The history was that at each menstrual period the woman sufifered greatly with neuralgic pains in the uterine region. These increased in severity, and after a time occurred as well in the face. This latter fact, coupled with the time at which the symptoms had first presented, which was directly after having a large amount of dentistry done, suggested to the mind of the husband that possibly the teeth might be the distant cause of all the trouble. My friend made an examination, and finding both central incisors pulpless, hazarded the removal of gold fillings, when he dis- covered that the roots were filled with cotton. This was removed, and after sterilization they were filled wath gutta-percha, and the cavities as before with gold. For six months the neuralgic pains occurred, only in much less severe shocks. As there was some improvement, the husband was encouraged, but decided that there might be other teeth in similar condition, and insisted upon the removal of all the fillings under which there was even a remote possibility of finding cotton. This resulted in such a discovery in three more teeth, and after proper treatment the patient was entirely restored to health. Never fill a root permanently with cotton. Cements. — The cements, so called, including oxy chloride and oxy- phosphate, must of course be relied upon in setting crowns, and therefore if they serve in those cases it follows that they must be 214 METHODS OF FILLING TEETH. reliable in any. This, however, must be modified, for where a crowrs is set, the canal is usually enlarged so considerably that the cement is readily carried to all parts of the root. Where the natural crown is still in place, it might not always be possible to thoroughly fill the canal with such a plastic material. Some claim that oxyphosphate lacks the virtues of oxychloride, but the statement, however authoritatively asserted, would be hard to prove. There is one objection to either which is important. It is difficult to remove them, should it be desir- able to empty the canal. Gutta-Percha. — This material, in some form, is used by the majority of dentists, and rightfully so. The usual custom is to roll the white variety into cones, which are slightly warmed and pressed into the canal. Chloro-percha is most useful when not relied upon alone. Forced into a canal and followed with a cone, it renders the operation of filling oftentimes more easy and more perfect. The form of gutta-percha which I prefer for root-filling is Gilbert's temporary stopping ; it is more readily made into cones, more easily softened by heat, and, in case of future necessity, more easily re- moved. My method of filling root-canals is as follows, and I may state that a perfect root- filling is possible wherever the Donaldson cleanser can be passed : Supposing that the tooth has been rendered healthy and aseptic, the canal is to be thoroughly heated. As hot as the patient will endure is my maxim. I next introduce a fine twist of absorbent cotton, dry, and I may here emphasize the need of having a fine gold or platinum canal-dressing instrument, which should never be used for any other purpose. Above all things do not hope for success if the roughened Donaldson bristle is thoughtlessly used for introducing a cotton dressing. The dry cotton having been tucked nicely into the root-canal, a larger ball of cotton is dipped in eucalyptus and placed in the cavity. By capillary attraction this agent rapidly passes into the dressing in the canal, thoroughly satu- rating it. I have adopted this method because I find the dry cotton more readily carried to the end of the canal than where it is charged with eucalyptus. My white temporary stopping is then prepared for the canal. Softened, it may be drawn out almost to a thread and is then permitted to harden, when one or two pieces barely an eighth of an inch in length are cut off. The cotton dressing is then re- moved, and thin chloro-percha passed into the canal, a tiny drop at a time on a smooth Donaldson bristle being worked up toward the apex. Next, the bristle is passed over the flame, warming it enough to pick up one of the little threads of gutta-percha, which is then passed gently up to the apex of the canal, care being taken not to press it beyond, which would be indicated by an expression of pain from the patient. This procedure should be so gradual that, should FILLING OF ROOT- CANALS. 215 such a signal be given, the operator could stop instantly, no harm having been done. It is well at this point to let matters rest for a minute or more, that the filling at the apex may become solidified, after which the remainder of the canal may be filled, using larger and larger threads or cones until all is completed. Should there present a case where there is doubt as to whether the root will tolerate a permanent root-filling, the following method will occasionally serve a good purpose : Take floss silk and wax it thoroughly, after which dip it into chloro-percha and cut it into pieces about an inch long. These, when dry, give us gutta-percha cones which have a silk through them. They are readily packed into a canal^ and the end being allowed to extend beyond the orifice of the canal, is readily grasped, in case of need, with a pair of tweezers, whe^^eupon the whole rootfilling is easily withdi'azvn. Where no trouble ensues, the root-filHng of this kind may safely be left in place, being quite dissimilar from cotton, as the silk fiber is thoroughly incased in gutta-percha. It may be argued that I should not advocate seemingly temporary methods ; but while it is true that we should hope to make our work as permanent as possible, in the matter of root-filling, too positive permanence is a detriment rather than an advantage. It never can te certainly asserted of any tooth that its roots will never need to be unfilled. If in no other way, the natural crown may continue to decay till it is lost, when a crowning process may make it imperative to empty the canal or canals. Where they are found filled with a very resistant material, there will always be some difficulty ex- perienced. Again, I have seen teeth lost, where pericementitis had set in, which could 7iot be adequately treated because the root- canals were so filled that they could not be emptied, the teeth being too sore to the touch to make the necessary work possible. When such a case pre- sents the dentist will quickly say to himself, " I wish this root were filled with temporary stopping, which I could remove with a heated instrument." Of course the other method, using the silk-and-gutta- percha cone, is satisfactory. Either of these methods require that at least a slight layer of oxy- phosphate or oxychloride should cover them before gold is packed upon them. This will be unnecessary where amalgam is to be de- pended upon. In concluding this work, I have only to state that in describing the methods that I have successfully used I do so with no special desire to impress my readers with the idea that they are .my methods. It seems to me immaterial who originates a method. The main thing is that it be useful. I have learned nearly "all that I know from others, and from experience. If I can now teach any one, it will be in some degree a repayment of the debt. INDEX. Abraded teeth, etiology of, 142. filling of, 142. use of screws in, no. Alloys, mixing of, 63, 67. Amalgam fillings, finishing of, 1S9. use of matrix in, 49, 64. where to use them, 65. Amalgams, combination of with other ma- terials, 66. in contour fillings, 105, 157. method of use, 63. relative values of, 62. shrinkage of, 62. where to use, 64. Ambidexterity, advantage of to the dentist, 88. Anchorage, difficulty of with sensitive dentine, 135- Approximal cavities, extension of, 16. preparation of, 6, 114, 131. rule for filling, 116. Approximal trimmer, use of in finishing fill- ings, 1S8. Arrested decay, 60. Arsenical dressings, covering of, 185. Arsenical poisoning, treatment of, 185. Artistic work, 138. Automatic mallet, use of, 87. Band, use of in filling-operations, 159, 182. in restoration of crowns, 113. Beveling enamel margins, 27, 132, 177. Bibulous paper, control of moisture by, 45. protection of gum-tissue by, 66. Bicuspid crown, relation of to the dental arch, 129. Bicuspids, filling of, 96, in, 12S, 131, 147, 175. roots of, 193. Bite, opening of, 144. Bpnwill mechanical mallet, 88. Bottomless cavities, 178. Bridge-piece, retention of by filling, 160. Buccal cavities, filling of, 180. Burnisher, use of in finishing fillings, 189. on sensitive teeth, 165. Burs, caution in use of, 24. Caries, susceptibility of human teeth to, 89. Cavities, classification of, 114, 163. general principles involved in preparation of, 2. Cavities, intentional extension of, 10, 14, n.s, 125, 130, 135, 137- methods of keeping dry, 28. special principles involved in preparation of, 114, 136, 163. Cavity borders, formation of, 19. Cement fillings, advantages of, 60. disadvantages of, 68. Cements as root-fillings, 213. modes of .mixing, 60, 61. where to use, 62, 82, 107, 109, 157. Cementum, sensitiveness of, 164. Central incisor, abrasion in, 142. approximal cavities in, 94, 115. contour filling of, 104, 107. restoration of cutting-edge, 15. root of, 191. Children's permanent teeth, filling of, 109. Chisel, use of in preparation of cavities, 150. Chloride of zinc as a germicide, 59. Chloro-percha as a root-filling, 214. cavity lining with, 58. control of moisture by, 45. Clamps, application of, 39. Cocaine, use of in applying ligatures, 32. Cohesive gold, manipulation of, 70. Compound cavities, 132. Contour fillings, burnishing of, 80. manipulation of, 91, 98. methods of producing, 102. use of amalgam in, 64. Copper amalgam, therapeutic value of, 68. Corners, fracture of by hand-pressure, 86. restoration of, 21, 119, 121, 122, 123, 131, 135, 139- Cotton as a root-filling, 213. as a temporary filling, 186. control of moisture by, 45. use of in festoon cavities, 31, 173. Crown, misuse of term, 114. restoration of, in, 112, 113. Crown cavities, choice of materials for filling, 65- . enlargement of, 155. preparation of, 9, 147. Crystal gold, 71, 139. methods of using, 72. Cuspids, contour filling of, 127. festoon cavity in, 175. 217 2l8 INDEX. Cuspids, incisive edge of, 145. microscopical section of, 164. roots of, 192. Cusps, restoration of with amalgam, 157. Cutting-edges, reproduction of, 97, 104, 121. Decay, removal of, 2, 146. Dental caries, production of by micro-organ- isms, 3. Dentine, preservation of in formation of cavi- ties, 141. sensitiveness of, 82, 164. Disk-carrier, best form of, 188. Disks, use of in finishing fillings, 26, 187, 189. Distal cavities in cuspids, 128. Donaldson canal-cleanser, 209. "Double teeth," 143. Drill, use of in root-canals, 204. Economy, true and false, 74, 76. Enamel, cleavage of, 22. contact of gold with, 141. effect of green-stain on, 170. sensitiveness of, 164. Enamel margins, 25. Erosion, caution in diagnosis, 166. distinction of from abrasion, 142. etiology of, 167. treatment of, 169. Evans clamp, proper use of, 40. Festoon cavities, preparation of, 9, 174. Figure-of-8 ligature, 35. File, use of, 90, 188. File-marks, avoidance of, 66. Filling-materials, varieties of, 49. Finishing of fillings, 1S7. Fissure cavities, preparation of, 11. Flat fillings, 95, 98. Foot-plugger, use of, 73, 79, 81, 103, 133. Fracture of amalgam fillings, 106. Fractured teeth, filling of, 36, 123, 140, 144. Frosted gold foil, 73. Gates-Glidden drill, 204. Germicides, combination of with oxyphos- phates, 61. Gingival border, failure of fillings at, 41, 65, 128, 132. Gold as a filling-material, 69, 130. as a root-filling, 212. combination of with oxyphosphate, 81. contour fillings, 102. how to condense, 85. incorporation of with amalgam, 64, 66. unsuitable cases for, 179. Gold and iridium, 85. Gold and platinum, 83. Gold and tin, 84. Gold fillings, finishing of, 187. for crown cavities, 65. leakage of, 4 , 66. use of matrix in, 48. Gravitation, effect of on fillings, 118, 122. Green-stain, 170, 1S2. Grinding-surfaces, reproduction of, 96. Grooved incisors, treatment of, 15. Grooved teeth, illustrations of, 168. Gum-recession, root-exposure from, 184. tooth-sensitiveness from, 163. Gum-tissue, arrangement of in man, 90. Gutta-percha as a filling-material, 56, 186. as a root-filling, 214. choice of colors, 57, 185. cones for root-filling, 215. finishing of, 189. Hand-Mallet, advantages of, 87, 175. - Hand-pressure, danger of fracture by, 121. in gold fillings, 85, 121. Hart, J. I., on sensitive dentine, 165. Heavy foil, manipulation of, 80, 103. uses of, 77, 132, 175. Heitzmann, C, microscopical section of cuspid, 164. Hollow fillings, 78, 102. Horse-shoe grooves, 151, 178. How cervix clamp, 41. How screws, use of, no. Hypersensitive teeth, gold fillings in, 82. Incisive edges, cavities in, 136, 144. contouring of, 141, 145. Incisors, filling of, 15, 92, 104, 107, no, in, 115 143- root-filling of, 191. Infected dentine, 3. Instruments, use of, 89, 175. Interzonal layer, sensitiveness of, 165. Iridium, combination of with gold, 85. Knots, methods of tying, 33. Labial cavities, filling of, 79, 116, 120, 133, 176. Lateral incisor, proneness of to abscess, 126. root of, 192. Lead as a filling-material, 50. as a root-filling, 212. Leakage of fillings, 41, 66. Ligatures, different forms of, 32. slipping of, 38. Lingual cavities, filling of, 379. Loose teeth, filling of, 34. fixation of, 162. Mallet, choice of, 87, 175. Mastication, effect of on the teeth, 92. fracture of fillings by, 106. Matrices, uses and dangers of, 47, 129, 187. Milk, production of green-stain by, 170. Miller, W. D., on green-stain, 170. Mixing-slab for oxyphosphates, 60. Moisture, devices for controlling, 45. in contour work, 106. recurrence of, 42. Molar crown, relation of to the dental arch, 129. Molars, enlargement of cavities in, 12. filling of, 95, 109, 112, 134. roots of, 208. Mouth, examination of, 148, 153. Mouth-mirror, use of, 118, 120, 121. Muffle for porcelain work, 54. INDEX. 219 Napkins, use of, 44. Nitrate of silver, use of on sensitive teetli, 166. Non-cohesive gold, use of, 70. Oven for baking- porcelain, 54. Oxychloride of zinc as a filling-nialenal, 58. Oxyphospliate of zinc, combination of with amalg-am, 67. combination of with gold. Si, 93, 157, 179. finishing of, 1S9. in contour work, 107. in crown-setting, 61. in festoon cavities, 173. manipulation of, 60. Palatal cavities, filling of, 178. Palato-approximal cavities, filling of, 120, 133, 180. Pellets for small cavities, 116, iSi. Pettit reamer, 207. Phosphate, combination of with amalgam, 67. Pin-head fillings, improper use of, 12. Pipe-clay disks for control of moisture, 45. Plastic gold, advantages of, 71. combination of with amalgam, 67. Platinum, combination of with gold, 83. Pluggers, choice of, SS. Polishing, best methods of, 26, 1S7, 189. Porcelain fillings, 50. anchored with gold, 55. Porcelain inlays, 50. Power mallet, unsuitable places for, 140, 175. Pressure, influence of on gold, S6. line of, 107, 152. Probational fillings, 1S4. Pulp, retention of dentine over, 146. size of determined by age, 134. Pulp-capping with gutta-percha, 58. Pyorrhea alveolaris resulting from wedging, 91 . Reamer, use of in root-canals, 207. Retaining-points, 122, 126, 133, 152, 181. Retentive shaping of cavities, 5, 130, 137. Root-canals, methods of cleansing, 209. preparation of, 202. when and how to fill, 212. Root-filling, difficulties of, 190. Roots, exposure of from gum-recession, 184. Rose bur, use of in preparation of cavities, 1 15. 125, 131- 136, 137. 140, 143- Rubber cup, use of in finishing fillings, 1S8. Rubber-dam, placing of, 29, 43. Rubber-dam, repair of, 44. Rubber tubing, use of in festoon cavities, 31, 173- Rubber wedge, use of, 46. Sandarac varnish, objections to, 185. Saucer-shaped cavities, 7, 78, 135. Screw-mandrel, advantages of, 188. Screws, use of, 109, 123, 124, 133, 144. Secondary dentine, formation of, 59. " Self-cleansing" surfaces, 17. Separators, abuse of, 45, 129. Silk and gutta-percha cones, 215. Sixth-year molar, filling of, 109. Soaping disks, 44. Sodium and potassium treatment of root- canals, 210. Space, necessity for in filling-operations, 129, 130. Sulci, reproduction of, 96. Surface cavities, 167. rarity of in incisors, 173. Syringe for cleansing root-canals, 210. Tape separators, 46. Teeth, change in position of, 97. decalcification of by green-stain, 1S3. occlusion of, 90. separation of, 90. shortening of bj- abrasion, 143. union of by a single filling, 160. Temporary fillings, 1S4. Temporary stopping, use of, 56, 185. Tin as a filling-material, 50, 184. comb'nation of with gold, 84. Tooth-brush, effect of on tooth-structure, 165. Tooth-neck, sensitiveness of, 105. Tooth-roots, varj'ing forms of, 190. Undercuts, filling of, 75. use of in preparation of cavities, 7, 9, 304, 115, 122, 127, 152. V-space, injurious results from, 91. Watts's crystal gold, 71. " \Vea\ing" method in ligatures, 37. I Wedges, use of, 45. Wheel-bur, use of in extension of cavities, 136. I Williams, J. L., theory of dental caries, 3. j Wisdom-teeth, roots of, 201. Wood as a root-filling, 212. I Wooden wedges, 47. Ot8 1899